Switch releases to Github CI

Improve stack GHC install script
Make stack GHC install hook posix compliant
2022-11-09 21:18:21 +08:00 · 2022-09-30 13:59:43 +08:00 · 2022-09-30 13:29:57 +08:00 · 2022-09-26 22:53:40 +08:00 · 2022-09-22 00:04:14 +08:00 · 2022-08-24 22:34:21 +08:00
97 changed files with 8532 additions and 5241 deletions
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -0,0 +1,15 @@
+freebsd_instance:
+  image_family: freebsd-13-1
+
+task:
+  env:
+    GHC_VER: 9.2.4
+    CABAL_VER: 3.6.2.0
+    ARTIFACT: "x86_64-portbld-freebsd-ghcup"
+    ARCH: 64
+    RUNNER_OS: FreeBSD
+  install_script: pkg install -y ghc hs-cabal-install git bash
+  script:
+    - bash .github/scripts/release.sh
+  binaries_artifacts:
+    path: "out/x86_64-portbld-freebsd-ghcup-*"
--- a/.github/scripts/release.sh
+++ b/.github/scripts/release.sh
@@ -0,0 +1,101 @@
+#!/bin/sh
+
+set -eux
+
+mkdir -p "$HOME"/.local/bin
+export PATH="$HOME/.local/bin:$PATH"
+
+if [ "${RUNNER_OS}" = "macOS" ] ; then
+	if ! command -v brew ; then
+		git clone --depth=1 https://github.com/Homebrew/brew "$HOME/.brew"
+		export PATH="$HOME/.brew/bin:$HOME/.brew/sbin:$PATH"
+		brew update
+	fi
+	brew install git
+fi
+
+if [ "${RUNNER_OS}" = "Linux" ] ; then
+          apk add --no-cache \
+            curl \
+            gcc \
+            g++ \
+            binutils \
+            binutils-gold \
+            bsd-compat-headers \
+            gmp-dev \
+            ncurses-dev \
+            libffi-dev \
+            make \
+            xz \
+            tar \
+            perl \
+            bash \
+            git
+
+          apk add --no-cache \
+            zlib \
+            zlib-dev \
+            zlib-static \
+            bzip2 \
+            bzip2-dev \
+            bzip2-static \
+            gmp \
+            gmp-dev \
+            openssl-dev \
+            openssl-libs-static \
+            xz \
+            xz-dev \
+            ncurses-static
+fi
+
+if ! command -v ghcup ; then
+  curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | BOOTSTRAP_HASKELL_NONINTERACTIVE=1 BOOTSTRAP_HASKELL_MINIMAL=1 sh
+  source ~/.ghcup/env
+fi
+
+
+if [ "${RUNNER_OS}" != "FreeBSD" ] ; then
+	ghcup install ghc --set --isolate="$HOME/.local" --force "$GHC_VER"
+	ghcup install cabal --isolate="$HOME/.local/bin" --force "$CABAL_VER"
+	ghc --version
+	cabal --version
+fi
+
+ecabal() {
+	cabal "$@"
+}
+
+git describe --all
+
+# build
+ecabal update
+
+
+if [ "${RUNNER_OS}" = "Linux" ] ; then
+	if [ "${ARCH}" = "32" ] ; then
+		ecabal build -w "ghc-${GHC_VER}" --ghc-options='-split-sections -optl-static' -ftui
+	elif [ "${ARCH}" = "64" ] ; then
+		ecabal build -w "ghc-${GHC_VER}" --ghc-options='-split-sections -optl-static' -ftui
+	else
+		ecabal build -w "ghc-${GHC_VER}" -ftui
+	fi
+elif [ "${RUNNER_OS}" = "FreeBSD" ] ; then
+	ecabal build -w "ghc-${GHC_VER}" --ghc-options='-split-sections' --constraint="zlib +bundled-c-zlib" --constraint="zip +disable-zstd" -ftui
+elif [ "${RUNNER_OS}" = "Windows" ] ; then
+	ecabal build -w "ghc-${GHC_VER}" --constraint="zlib +bundled-c-zlib" --constraint="lzma +static"
+else
+	ecabal build -w "ghc-${GHC_VER}" --constraint="zlib +bundled-c-zlib" --constraint="lzma +static" -ftui
+fi
+
+mkdir out
+binary=$(ecabal new-exec -w "ghc-${GHC_VER}" --verbose=0 --offline sh -- -c 'command -v ghcup')
+ver=$("${binary}" --numeric-version)
+if [ "${RUNNER_OS}" = "macOS" ] ; then
+	strip "${binary}"
+else
+	if [ "${RUNNER_OS}" != "Windows" ] ; then
+		strip -s "${binary}"
+	fi
+fi
+cp "${binary}" "out/${ARTIFACT}-${ver}"
+
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -6,104 +6,80 @@ on:
      - 'v*'

 jobs:
-  draft_release:
-    name: Draft Release
-    runs-on: ubuntu-latest
-    outputs:
-      upload_url: ${{ steps.create_release.outputs.upload_url }}
-
-    steps:
-      - name: Create Release
-        id: create_release
-        uses: actions/create-release@v1
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          tag_name: ${{ github.ref }}
-          release_name: Release ${{ github.ref }}
-          body: |
-            Changes in this Release
-            - First Change
-            - Second Change
-          draft: true
-          prerelease: false
-
-  release-mac:
-    name: Create Release
-    needs: draft_release
+  release-linux:
+    name: Create Release x86_64
    runs-on: ${{ matrix.os }}
    env:
+      CABAL_VER: 3.6.2.0
+      CACHE_VER: 1
      MACOSX_DEPLOYMENT_TARGET: 10.13
    strategy:
      matrix:
-        os:
-          - macOS-10.15
+        include:
+          - os: ubuntu-latest
+            ARTIFACT: "i386-linux-ghcup"
+            GHC_VER: 8.10.7
+            ARCH: 32
+          - os: ubuntu-latest
+            ARTIFACT: "x86_64-linux-ghcup"
+            GHC_VER: 8.10.7
+            ARCH: 64
+          - os: [self-hosted, macOS, aarch64]
+            ARTIFACT: "aarch64-apple-darwin-ghcup"
+            GHC_VER: 9.2.5
+            ARCH: 64
+          - os: macOS-10.15
+            ARTIFACT: "x86_64-apple-darwin-ghcup"
+            GHC_VER: 9.2.5
+            ARCH: 64
+          - os: windows-latest
+            ARTIFACT: "x86_64-mingw64-ghcup"
+            GHC_VER: 8.10.7
+            ARCH: 64
    steps:
      - name: Checkout code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3

-      - uses: haskell/actions/setup@v1.2
+      - if: matrix.ARCH == '32' && runner.os == 'Linux'
+        name: Run release (32 bit linux)
+        uses: docker://i386/alpine:3.12
        with:
-          ghc-version: 8.10.7
-          cabal-version: 3.6.2.0
-
-      - name: create ~/.local/bin
-        run: mkdir -p "$HOME/.local/bin"
-        shell: bash
-
-      - name: Add ~/.local/bin to PATH
-        run: echo "$HOME/.local/bin" >> $GITHUB_PATH
-        shell: bash
-
-      - name: Update cabal cache
-        run: cabal update
-        shell: bash
-
-      - name: Install cabal dependencies
-        run: cabal build --only-dependencies --constraint="zlib +bundled-c-zlib" --constraint="lzma +static" -ftui
-        shell: bash
-
-      - name: Build
-        run: cabal build --constraint="zlib +bundled-c-zlib" --constraint="lzma +static" -ftui
-        shell: bash
-
-      - name: Install
-        run: cp "$(cabal list-bin exe:ghcup)" ~/.local/bin/ghcup
-        shell: bash
-
-      - name: Strip
-        run: strip ~/.local/bin/ghcup
-        shell: bash
-
-      - name: Run tests
-        run: cabal test --constraint="zlib +bundled-c-zlib" --constraint="lzma +static" all
-        shell: bash
-
-      - name: Install git
-        run: brew install git
-
-      - name: set HOME
-        run: echo "HOME=$HOME" >> $GITHUB_ENV
-        shell: bash
-
-      - name: Set ASSET_PATH
-        run: echo "ASSET_PATH=$HOME/.local/bin/ghcup" >> $GITHUB_ENV
-        shell: bash
-
-      - name: Upload Release Asset
-        id: upload-release-asset
-        uses: actions/upload-release-asset@v1
+          args: sh .github/scripts/release.sh
        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ARTIFACT: ${{ matrix.ARTIFACT }}
+          ARCH: ${{ matrix.ARCH }}
+          GHC_VER: ${{ matrix.GHC_VER }}
+
+      - if: matrix.ARCH == '64' && runner.os == 'Linux'
+        name: Run release (64 bit linux)
+        uses: docker://alpine:3.12
        with:
-          upload_url: ${{ needs.draft_release.outputs.upload_url }}
-          asset_path: ${{ env.ASSET_PATH }}
-          asset_name: ghcup-${{ matrix.os }}
-          asset_content_type: application/octet-stream
+          args: sh .github/scripts/release.sh
+        env:
+          ARTIFACT: ${{ matrix.ARTIFACT }}
+          ARCH: ${{ matrix.ARCH }}
+          GHC_VER: ${{ matrix.GHC_VER }}
+
+      - if: runner.os != 'Linux'
+        name: Run release (windows/mac)
+        run: bash .github/scripts/release.sh
+        env:
+          ARTIFACT: ${{ matrix.ARTIFACT }}
+          ARCH: ${{ matrix.ARCH }}
+          GHC_VER: ${{ matrix.GHC_VER }}

      - if: always()
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
        with:
-          name: plan.json
-          path: ./dist-newstyle/cache/plan.json
+          name: artifacts
+          path: |
+            ./out/*
+            ./dist-newstyle/cache/plan.json

+      - name: Release
+        uses: softprops/action-gh-release@v1
+        with:
+          draft: true
+          files: |
+            ./out/*
+            ./dist-newstyle/cache/plan.json
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -13,7 +13,7 @@ variables:

  # Sequential version number of all cached things.
  # Bump to invalidate GitLab CI cache.
-  CACHE_REV: 0
+  CACHE_REV: 1

  GIT_SUBMODULE_STRATEGY: recursive

@@ -125,6 +125,10 @@ variables:
      - test/golden
      - dist-newstyle/cache/
    when: on_failure
+  cache:
+    key: ghcup-test-$CACHE_REV
+    paths:
+      - cabal-cache

 # .test_ghcup_scoop:
  # script:
@@ -136,6 +140,10 @@ variables:
    - .debian
  before_script:
    - ./.gitlab/before_script/linux/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:linux32:
  extends:
@@ -143,6 +151,10 @@ variables:
    - .alpine:32bit
  before_script:
    - ./.gitlab/before_script/linux/alpine/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:armv7:
  extends:
@@ -150,6 +162,10 @@ variables:
    - .linux:armv7
  before_script:
    - ./.gitlab/before_script/linux/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:aarch64:
  extends:
@@ -157,45 +173,42 @@ variables:
    - .linux:aarch64
  before_script:
    - ./.gitlab/before_script/linux/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:darwin:
  extends:
    - .test_ghcup_version
    - .darwin
-    - .root_cleanup
  before_script:
    - ./.gitlab/before_script/darwin/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:darwin:aarch64:
  extends:
    - .test_ghcup_version
    - .darwin:aarch64
-    - .root_cleanup
  cache:
    key: darwin-brew-$CACHE_REV
    paths:
-      - .brew
-      - .brew_cache
+      - brew_cache
+    key: ghcup-test-$CACHE_REV
+    paths:
+      - cabal-cache
  before_script:
-    # Install brew locally in the project dir. Packages will also be installed here.
-    - '[ -e "$CI_PROJECT_DIR/.brew" ] || git clone --depth=1 https://github.com/Homebrew/brew $CI_PROJECT_DIR/.brew'
-    - export PATH="$CI_PROJECT_DIR/.brew/bin:$CI_PROJECT_DIR/.brew/sbin:$PATH"
-
+    # extract brew cache
+    - ./.gitlab/script/ci.sh extract_brew_cache
    # otherwise we seem to get intel binaries
    - export HOMEBREW_CHANGE_ARCH_TO_ARM=1
-
-    # make sure to not pollute the machine with temp files etc
-    - mkdir -p $CI_PROJECT_DIR/.brew_cache
-    - export HOMEBREW_CACHE=$CI_PROJECT_DIR/.brew_cache
-    - mkdir -p $CI_PROJECT_DIR/.brew_logs
-    - export HOMEBREW_LOGS=$CI_PROJECT_DIR/.brew_logs
-    - mkdir -p /private/tmp/.brew_tmp
-    - export HOMEBREW_TEMP=/private/tmp/.brew_tmp
-
    # update and install packages
-    - brew update
-    - brew install llvm
-    - brew install autoconf automake coreutils
+    - /bin/bash ./.gitlab/script/brew.sh llvm autoconf automake coreutils
+    # extract cabal cache
+    - ./.gitlab/script/ci.sh extract_cabal_cache
  script: |
    export PATH="$CI_PROJECT_DIR/.brew/opt/llvm/bin:$CI_PROJECT_DIR/.brew/bin:$CI_PROJECT_DIR/.brew/sbin:$PATH"
    export CC=$CI_PROJECT_DIR/.brew/opt/llvm/bin/clang
@@ -205,40 +218,51 @@ variables:
    export RANLIB=$CI_PROJECT_DIR/.brew/opt/llvm/bin/llvm-ranlib
    ./.gitlab/before_script/darwin/install_deps.sh
    ./.gitlab/script/ghcup_version.sh
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - ./.gitlab/script/ci.sh save_brew_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:freebsd12:
  extends:
    - .test_ghcup_version
    - .freebsd12
-    - .root_cleanup
  before_script:
    - ./.gitlab/before_script/freebsd/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:freebsd13:
  extends:
    - .test_ghcup_version
    - .freebsd13
-    - .root_cleanup
  before_script:
    - sudo pkg update
    - sudo pkg install --yes compat12x-amd64
    - sudo ln -s libncurses.so.6 /usr/local/lib/libncurses.so.6.2
    - ./.gitlab/before_script/freebsd/install_deps.sh
+    - ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 .test_ghcup_version:windows:
  extends:
    - .test_ghcup_version
    - .windows
-    - .root_cleanup
  before_script:
-    - set CABAL_DIR="$CI_PROJECT_DIR/cabal"
    - bash ./.gitlab/before_script/windows/install_deps.sh
+    - bash ./.gitlab/script/ci.sh extract_cabal_cache
+  after_script:
+    - bash ./.gitlab/script/ci.sh save_cabal_cache
+    - bash ./.gitlab/after_script.sh

 # .test_ghcup_scoop:windows:
  # extends:
    # - .windows
    # - .test_ghcup_scoop
-    # - .root_cleanup

 .release_ghcup:
  script:
@@ -258,9 +282,12 @@ variables:
 test:linux:stack:
  stage: test
  before_script:
+    - ./.gitlab/script/ci.sh extract_stack_cache
    - ./.gitlab/before_script/linux/install_deps_minimal.sh
  script:
    - ./.gitlab/script/ghcup_stack.sh
+  after_script:
+    - ./.gitlab/script/ci.sh save_stack_cache
  extends:
    - .debian
  needs: []
@@ -290,6 +317,7 @@ test:windows:bootstrap_powershell_script:
    - "[Environment]::SetEnvironmentVariable('GHCUP_MSYS2', $null, [System.EnvironmentVariableTarget]::User)"
    - "[Environment]::SetEnvironmentVariable('CABAL_DIR', $null, [System.EnvironmentVariableTarget]::User)"
    - bash ./.gitlab/after_script.sh
+    - bash ./.gitlab/script/ci.sh save_cabal_cache
  variables:
    GHC_VERSION: "8.10.7"
    CABAL_VERSION: "3.6.2.0"
@@ -536,28 +564,17 @@ release:darwin:aarch64:
  cache:
    key: darwin-brew-$CACHE_REV
    paths:
-      - .brew
-      - .brew_cache
+      - brew_cache
+    key: ghcup-test-$CACHE_REV
+    paths:
+      - cabal-cache
  before_script:
-    # Install brew locally in the project dir. Packages will also be installed here.
-    - '[ -e "$CI_PROJECT_DIR/.brew" ] || git clone --depth=1 https://github.com/Homebrew/brew $CI_PROJECT_DIR/.brew'
-    - export PATH="$CI_PROJECT_DIR/.brew/bin:$CI_PROJECT_DIR/.brew/sbin:$PATH"
-
+    - ./.gitlab/script/ci.sh extract_brew_cache
+    - ./.gitlab/script/ci.sh extract_cabal_cache
    # otherwise we seem to get intel binaries
    - export HOMEBREW_CHANGE_ARCH_TO_ARM=1
-
-    # make sure to not pollute the machine with temp files etc
-    - mkdir -p $CI_PROJECT_DIR/.brew_cache
-    - export HOMEBREW_CACHE=$CI_PROJECT_DIR/.brew_cache
-    - mkdir -p $CI_PROJECT_DIR/.brew_logs
-    - export HOMEBREW_LOGS=$CI_PROJECT_DIR/.brew_logs
-    - mkdir -p /private/tmp/.brew_tmp
-    - export HOMEBREW_TEMP=/private/tmp/.brew_tmp
-
    # update and install packages
-    - brew update
-    - brew install llvm
-    - brew install autoconf automake
+    - /bin/bash ./.gitlab/script/brew.sh llvm autoconf automake coreutils
  script: |
    export PATH="$CI_PROJECT_DIR/.brew/opt/llvm/bin:$CI_PROJECT_DIR/.brew/bin:$CI_PROJECT_DIR/.brew/sbin:$PATH"
    export CC=$CI_PROJECT_DIR/.brew/opt/llvm/bin/clang
@@ -567,6 +584,9 @@ release:darwin:aarch64:
    export RANLIB=$CI_PROJECT_DIR/.brew/opt/llvm/bin/llvm-ranlib
    ./.gitlab/before_script/darwin/install_deps.sh
    ./.gitlab/script/ghcup_release.sh
+  after_script:
+    - ./.gitlab/script/ci.sh save_cabal_cache
+    - ./.gitlab/script/ci.sh save_brew_cache
  variables:
    ARTIFACT: "aarch64-apple-darwin-ghcup"
    GHC_VERSION: "8.10.7"
--- a/.gitlab/ghcup_env
+++ b/.gitlab/ghcup_env
@@ -1,11 +1,23 @@
 if [ "${OS}" = "WINDOWS" ] ; then
-	export GHCUP_INSTALL_BASE_PREFIX="$CI_PROJECT_DIR"
-	export GHCUP_BIN="$CI_PROJECT_DIR/ghcup/bin"
-	export PATH="$GHCUP_BIN:$CI_PROJECT_DIR/.local/bin:$PATH"
-	export TMPDIR="$CI_PROJECT_DIR/tmp"
+    export GHCUP_INSTALL_BASE_PREFIX="$CI_PROJECT_DIR"
+    export GHCUP_BIN="$CI_PROJECT_DIR/ghcup/bin"
+    export PATH="$GHCUP_BIN:$CI_PROJECT_DIR/.local/bin:$PATH"
+    export TMPDIR="$CI_PROJECT_DIR/tmp"
+    export CABAL_DIR="$CI_PROJECT_DIR/cabal"
+    export CABAL_CACHE="$CI_PROJECT_DIR/cabal-cache"
+    export STACK_ROOT="$CI_PROJECT_DIR/stack"
+    export STACK_CACHE="$CI_PROJECT_DIR/stack-cache"
+    export BREW_DIR="$CI_PROJECT_DIR/.brew_cache"
+    export BREW_CACHE="$CI_PROJECT_DIR/brew-cache"
 else
-	export GHCUP_INSTALL_BASE_PREFIX="$CI_PROJECT_DIR"
-	export GHCUP_BIN="$CI_PROJECT_DIR/.ghcup/bin"
-	export PATH="$GHCUP_BIN:$CI_PROJECT_DIR/.local/bin:$PATH"
-	export TMPDIR="$CI_PROJECT_DIR/tmp"
+    export GHCUP_INSTALL_BASE_PREFIX="$CI_PROJECT_DIR"
+    export GHCUP_BIN="$CI_PROJECT_DIR/.ghcup/bin"
+    export PATH="$GHCUP_BIN:$CI_PROJECT_DIR/.local/bin:$PATH"
+    export TMPDIR="$CI_PROJECT_DIR/tmp"
+    export CABAL_DIR="$CI_PROJECT_DIR/cabal"
+    export CABAL_CACHE="$CI_PROJECT_DIR/cabal-cache"
+    export STACK_ROOT="$CI_PROJECT_DIR/stack"
+    export STACK_CACHE="$CI_PROJECT_DIR/stack-cache"
+    export BREW_DIR="$CI_PROJECT_DIR/.brew_cache"
+    export BREW_CACHE="$CI_PROJECT_DIR/brew-cache"
 fi
--- a/.gitlab/script/brew.sh
+++ b/.gitlab/script/brew.sh
@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+set -Eeuxo pipefail
+
+# Install brew locally in the project dir. Packages will also be installed here.
+[ -e "$CI_PROJECT_DIR/.brew" ] || git clone --depth=1 https://github.com/Homebrew/brew $CI_PROJECT_DIR/.brew
+export PATH="$CI_PROJECT_DIR/.brew/bin:$CI_PROJECT_DIR/.brew/sbin:$PATH"
+
+# make sure to not pollute the machine with temp files etc
+mkdir -p $CI_PROJECT_DIR/.brew_cache
+export HOMEBREW_CACHE=$CI_PROJECT_DIR/.brew_cache
+mkdir -p $CI_PROJECT_DIR/.brew_logs
+export HOMEBREW_LOGS=$CI_PROJECT_DIR/.brew_logs
+mkdir -p /private/tmp/.brew_tmp
+export HOMEBREW_TEMP=/private/tmp/.brew_tmp
+
+# update and install packages
+brew update
+brew install ${1+"$@"}
--- a/.gitlab/script/ci.sh
+++ b/.gitlab/script/ci.sh
@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+set -Eeuo pipefail
+
+TOP="$( cd "$(dirname "$0")" ; pwd -P )"
+. "${TOP}/../ghcup_env"
+
+function save_cabal_cache () {
+  echo "Storing cabal cache from $CABAL_DIR to $CABAL_CACHE..."
+  rm -Rf "$CABAL_CACHE"
+  mkdir -p "$CABAL_CACHE"
+  if [ -d "$CABAL_DIR" ]; then
+	  cp -Rf "$CABAL_DIR" "$CABAL_CACHE/"
+  fi
+}
+
+
+function extract_cabal_cache () {
+  if [ -d "$CABAL_CACHE" ]; then
+      echo "Extracting cabal cache from $CABAL_CACHE to $CABAL_DIR..."
+      mkdir -p "$CABAL_DIR"
+      cp -Rf "$CABAL_CACHE"/* "$CABAL_DIR"
+  fi
+}
+
+function save_stack_cache () {
+  echo "Storing stack cache from $STACK_ROOT to $STACK_CACHE..."
+  rm -Rf "$STACK_CACHE"
+  mkdir -p "$STACK_CACHE"
+  if [ -d "$STACK_ROOT" ]; then
+	  cp -Rf "$STACK_DIR" "$STACK_CACHE"
+  fi
+}
+
+
+function extract_stack_cache () {
+  if [ -d "$STACK_CACHE" ]; then
+      echo "Extracting stack cache from $STACK_CACHE to $STACK_ROOT..."
+      mkdir -p "$STACK_ROOT"
+      cp -Rf "$STACK_CACHE"/* "$STACK_ROOT"
+  fi
+}
+
+function save_brew_cache () {
+  echo "Storing brew cache from $BREW_DIR to $BREW_CACHE..."
+  rm -Rf "$BREW_CACHE"
+  mkdir -p "$BREW_CACHE"
+  if [ -d "$BREW_DIR" ]; then
+	  cp -Rf "$BREW_DIR" "$BREW_CACHE"
+  fi
+}
+
+
+function extract_brew_cache () {
+  if [ -d "$BREW_CACHE" ]; then
+      echo "Extracting stack cache from $BREW_CACHE to $BREW_DIR..."
+      mkdir -p "$BREW_DIR"
+      cp -Rf "$BREW_CACHE"/* "$BREW_DIR"
+  fi
+}
+
+case $1 in
+  extract_cabal_cache) extract_cabal_cache ;;
+  save_cabal_cache) save_cabal_cache ;;
+  extract_stack_cache) extract_stack_cache ;;
+  save_stack_cache) save_stack_cache ;;
+  extract_brew_cache) extract_brew_cache ;;
+  save_brew_cache) save_brew_cache ;;
+  *) echo "unknown mode $1" ; exit 11 ;;
+esac
--- a/.gitlab/script/ghcup_bootstrap.sh
+++ b/.gitlab/script/ghcup_bootstrap.sh
@@ -6,20 +6,10 @@ set -eux

 mkdir -p "$CI_PROJECT_DIR"/.local/bin

-ecabal() {
-	cabal "$@"
-}
-
-eghcup() {
-	ghcup -v -c -s file://$(pwd)/ghcup-${JSON_VERSION}.yaml "$@"
-}
-
 git describe --always

 ### build

-ecabal update
-
 export BOOTSTRAP_HASKELL_NONINTERACTIVE=yes
 export BOOTSTRAP_HASKELL_GHC_VERSION=$GHC_VERSION
 export BOOTSTRAP_HASKELL_CABAL_VERSION=$CABAL_VERSION
--- a/.gitlab/script/ghcup_version.sh
+++ b/.gitlab/script/ghcup_version.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash

 set -eux

@@ -8,6 +8,7 @@ mkdir -p "$CI_PROJECT_DIR"/.local/bin

 CI_PROJECT_DIR=$(pwd)

+
 ecabal() {
 	cabal "$@"
 }
@@ -34,6 +35,8 @@ git describe --always

 ### build

+rm -rf "${GHCUP_DIR}"/share
+
 ecabal update

 if [ "${OS}" = "DARWIN" ] ; then
@@ -94,16 +97,23 @@ rm -rf "${GHCUP_DIR}"
 eghcup --numeric-version

 eghcup install ghc ${GHC_VERSION}
-[ `$(eghcup whereis ghc ${GHC_VERSION}) --numeric-version` = "${GHC_VERSION}" ]
-[ `eghcup run --ghc ${GHC_VERSION} -- ghc --numeric-version` = "${GHC_VERSION}" ]
+eghcup unset ghc ${GHC_VERSION}
+ls -lah "$(eghcup whereis -d ghc ${GHC_VERSION})"
+[ "`$(eghcup whereis ghc ${GHC_VERSION}) --numeric-version`" = "${GHC_VERSION}" ]
+[ "`eghcup run --ghc ${GHC_VERSION} -- ghc --numeric-version`" = "${GHC_VERSION}" ]
+[ "`ghcup run --ghc ${GHC_VERSION} -- ghc -e 'Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)'`" = "`$(ghcup whereis ghc ${GHC_VERSION}) -e 'Control.Monad.join (Control.Monad.fmap System.IO.putStr System.Environment.getExecutablePath)'`" ]
 eghcup set ghc ${GHC_VERSION}
 eghcup install cabal ${CABAL_VERSION}
-[ `$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version` = "${CABAL_VERSION}" ]
+[ "`$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version`" = "${CABAL_VERSION}" ]
 eghcup unset cabal
-"$GHCUP_BIN"/cabal --version && exit || echo yes
+"$GHCUP_BIN"/cabal --version && exit 1 || echo yes
+
+# make sure no cabal is set when running 'ghcup run' to check that PATH propagages properly
+# https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/375
+[ "`eghcup run --cabal ${CABAL_VERSION} -- cabal --numeric-version`" = "${CABAL_VERSION}" ]
 eghcup set cabal ${CABAL_VERSION}
-[ `$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version` = "${CABAL_VERSION}" ]
-[ `eghcup run --cabal ${CABAL_VERSION} -- cabal --numeric-version` = "${CABAL_VERSION}" ]
+
+[ "`$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version`" = "${CABAL_VERSION}" ]

 if [ "${OS}" != "FREEBSD" ] ; then
 	if [ "${ARCH}" = "64" ] ; then
@@ -170,12 +180,14 @@ else
 	eghcup set ${GHC_VERSION}
 	[ "$(ghc --numeric-version)" = "${ghc_ver}" ]
 	eghcup unset ghc
-    "$GHCUP_BIN"/ghc --numeric-version && exit || echo yes
+    "$GHCUP_BIN"/ghc --numeric-version && exit 1 || echo yes
 	eghcup set ${GHC_VERSION}
 	eghcup --offline rm 8.10.3
 	[ "$(ghc --numeric-version)" = "${ghc_ver}" ]


+	ls -lah "$GHCUP_BIN"
+
 	if [ "${OS}" = "DARWIN" ] ; then
 		eghcup install hls
 		$(eghcup whereis hls) --version
@@ -187,12 +199,12 @@ else
 			eghcup install hls
 			haskell-language-server-wrapper --version
 			eghcup unset hls
-			"$GHCUP_BIN"/haskell-language-server-wrapper --version && exit || echo yes
+			"$GHCUP_BIN"/haskell-language-server-wrapper --version && exit 1 || echo yes

 			eghcup install stack
 			stack --version
-			eghcup unset hls
-			"$GHCUP_BIN"/stack --version && exit || echo yes
+			eghcup unset stack
+			"$GHCUP_BIN"/stack --version && exit 1 || echo yes
 		fi
 	fi
 fi
@@ -210,11 +222,13 @@ eghcup rm $(ghc --numeric-version)
 # https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/116
 if [ "${OS}" = "LINUX" ] ; then
 	if [ "${ARCH}" = "64" ] ; then
-		eghcup install cabal -u https://oleg.fi/cabal-install-3.4.0.0-rc4/cabal-install-3.4.0.0-x86_64-ubuntu-16.04.tar.xz 3.4.0.0-rc4
+		eghcup install cabal -u https://downloads.haskell.org/~ghcup/unofficial-bindists/cabal/3.7.0.0-pre20220407/cabal-install-3.7-x86_64-linux-alpine.tar.xz 3.4.0.0-rc4
 		eghcup rm cabal 3.4.0.0-rc4
 	fi
 fi

+eghcup gc -c
+
 sha_sum() {
 	if [ "${OS}" = "FREEBSD" ] ; then
 		sha256 "$@"
@@ -262,13 +276,39 @@ if [ "${ARCH}" = "64" ] ; then
 		eghcup install hls -i "$(pwd)/isolated" 1.3.0
 		[ "$(isolated/haskell-language-server-wrapper --numeric-version)" = "1.3.0" ] ||
 			[ "$(isolated/haskell-language-server-wrapper --numeric-version)" = "1.3.0.0" ]
+
+		# test that isolated installs don't clean up target directory
+		cat <<EOF > "${GHCUP_BIN}/gmake"
+#!/bin/bash
+exit 1
+EOF
+		chmod +x "${GHCUP_BIN}/gmake"
+		mkdir isolated_tainted/
+		touch isolated_tainted/lol
+
+		! eghcup install ghc -i "$(pwd)/isolated_tainted" 8.10.5 --force
+		[ -e "$(pwd)/isolated_tainted/lol" ]
+		rm "${GHCUP_BIN}/gmake"
 	fi
 fi

 eghcup upgrade
 eghcup upgrade -f

+# test that doing fishy symlinks into GHCup dir doesn't cause weird stuff on 'ghcup nuke'
+mkdir no_nuke/
+mkdir no_nuke/bar
+echo 'foo' > no_nuke/file
+echo 'bar' > no_nuke/bar/file
+ln -s "$CI_PROJECT_DIR"/no_nuke/ "${GHCUP_DIR}"/cache/no_nuke
+ln -s "$CI_PROJECT_DIR"/no_nuke/ "${GHCUP_DIR}"/logs/no_nuke

 # nuke
 eghcup nuke
 [ ! -e "${GHCUP_DIR}" ]
+
+# make sure nuke doesn't resolve symlinks
+[ -e "$CI_PROJECT_DIR"/no_nuke/file ]
+[ -e "$CI_PROJECT_DIR"/no_nuke/bar/file ]
+
+
--- a/.hlint.yaml
+++ b/.hlint.yaml
@@ -20,6 +20,7 @@
 - ignore: {name: "Avoid lambda"}
 - ignore: {name: "Use uncurry"}
 - ignore: {name: "Use replicateM"}
+- ignore: {name: "Use unless"}
 - ignore: {name: "Redundant irrefutable pattern"}


--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,53 @@
 # Revision history for ghcup

+## 0.1.18.1 -- 2022-08-06
+
+* fix sdist and unbreak hackage, wrt [#399](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/399)
+
+## 0.1.18.0 -- 2022-07-30
+
+* Fix tui set wrt [#266](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/266) by Arjun Kathuria
+    - Ask the user to install the tool via prompt when setting an non-installed version
+* improvements to safe (un-)installations
+    - bindists that don't support `make DESTDIR=/some/tmp/dir install` are now unsupported
+    - installed GHC files are now recorded to avoid use of `removePathForcibly`
+    - internally uses a newtype wrapper for user-input paths and restrict destructive operations to validated paths
+* Add `--disable-ld-override` for darwin bindists wrt #391
+* Allow passing bindist configure args wrt #377
+* use of `TMPDIR` is dropped... now uses an internal tmp dir `~/.ghcup/tmp`
+* improvements to error handling and warnings
+* Require --isolate to have an absolute directory, fixes #367
+* Fix mingw PATH handling wrt #371
+* Add --mingw-path switch to `ghcup run`
+* Fix `ghcup run` on windows, fixes #375
+* Improve `ghcup compile <hls|ghc>`
+    - short hashes now work
+    - print the long hash in addition to the detected version
+* Improve `ghcup compile hls`
+    - add `--git-describe-version` switch as an alternative to `--overwrite-version`
+    - Allow to build HLS from hackage (now is the default)
+	- Allow to run 'cabal update' automatically before the HLS build
+	- Fix parser and completer for 'ghcup compile hls --version'
+* Improve `ghcup compile ghc`
+    - Allow to build from arbitrary GHC source dists
+
+## 0.1.17.10 -- 2022-05-12
+
+* windows hotfix (hackage-only release)
+
+## 0.1.17.9 -- 2022-05-12
+
+* broken sdist (hackage-only release)
+
+## 0.1.17.8 -- 2022-05-11
+
+* Fix a serious (but hard to trigger) bug when combining `--isolate <DIR>` with `--force`, please make sure to upgrade or avoid `--force`
+* Fix HLS build not cleaning up properly on failed installations, fixes [#361](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/361)
+* Fix parsing of symlinks with multiple slashes, wrt [#353](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/353)
+* Re-enable upgrade functionality for all configurations wrt [MR #250](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/250) and [VSCode haskell issue #601](https://github.com/haskell/vscode-haskell/issues/601)
+* Fix `ghcup run --ghc 8.10` (for short versions) wrt [#360](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/360)
+    - this also introduces a `--quick` switch for `ghcup run`
+
 ## 0.1.17.7 -- 2022-04-21

 * Fix `ghcup run` on windows wrt [#345](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/345)
--- a/app/ghcup/BrickMain.hs
+++ b/app/ghcup/BrickMain.hs
@@ -13,9 +13,11 @@ import           GHCup.Errors
 import           GHCup.Types.Optics ( getDirs )
 import           GHCup.Types         hiding ( LeanAppState(..) )
 import           GHCup.Utils
-import           GHCup.Utils.Logger
-import           GHCup.Utils.Prelude ( decUTF8Safe )
-import           GHCup.Utils.File
+import           GHCup.Prelude ( decUTF8Safe )
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.Process
+import           GHCup.Prompts

 import           Brick
 import           Brick.Widgets.Border
@@ -44,7 +46,6 @@ import           Data.Vector                    ( Vector
 import           Data.Versions           hiding ( str )
 import           Haskus.Utils.Variant.Excepts
 import           Prelude                 hiding ( appendFile )
-import           System.Directory               ( canonicalizePath )
 import           System.FilePath
 import           System.Exit
 import           System.IO.Unsafe
@@ -52,6 +53,8 @@ import           Text.PrettyPrint.HughesPJClass ( prettyShow )
 import           URI.ByteString

 import qualified Data.Text                     as T
+import qualified Data.Text.Lazy.Builder        as B
+import qualified Data.Text.Lazy                as L
 import qualified Graphics.Vty                  as Vty
 import qualified Data.Vector                   as V
 import System.Environment (getExecutablePath)
@@ -98,7 +101,7 @@ keyHandlers KeyBindings {..} =
  [ (bQuit, const "Quit"     , halt)
  , (bInstall, const "Install"  , withIOAction install')
  , (bUninstall, const "Uninstall", withIOAction del')
-  , (bSet, const "Set"      , withIOAction ((liftIO .) . set'))
+  , (bSet, const "Set"      , withIOAction set')
  , (bChangelog, const "ChangeLog", withIOAction changelog')
  , ( bShowAllVersions
    , \BrickSettings {..} ->
@@ -437,6 +440,9 @@ install' _ (_, ListResult {..}) = do
              , TarDirDoesNotExist
              , FileAlreadyExistsError
              , ProcessError
+              , ToolShadowed
+              , UninstallFailed
+              , MergeFileTreeError
              ]

  run (do
@@ -446,19 +452,19 @@ install' _ (_, ListResult {..}) = do
      case lTool of
        GHC   -> do
          let vi = getVersionInfo lVer GHC dls
-          liftE $ installGHCBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installGHCBin lVer GHCupInternal False [] $> (vi, dirs, ce)
        Cabal -> do
          let vi = getVersionInfo lVer Cabal dls
-          liftE $ installCabalBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installCabalBin lVer GHCupInternal False $> (vi, dirs, ce)
        GHCup -> do
          let vi = snd <$> getLatest dls GHCup
-          liftE $ upgradeGHCup Nothing False $> (vi, dirs, ce)
+          liftE $ upgradeGHCup Nothing False False $> (vi, dirs, ce)
        HLS   -> do
          let vi = getVersionInfo lVer HLS dls
-          liftE $ installHLSBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installHLSBin lVer GHCupInternal False $> (vi, dirs, ce)
        Stack -> do
          let vi = getVersionInfo lVer Stack dls
-          liftE $ installStackBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installStackBin lVer GHCupInternal False $> (vi, dirs, ce)
    )
    >>= \case
          VRight (vi, Dirs{..}, Just ce) -> do
@@ -483,9 +489,12 @@ install' _ (_, ListResult {..}) = do
            <> "Also check the logs in ~/.ghcup/logs"


-set' :: BrickState -> (Int, ListResult) -> IO (Either String ())
-set' _ (_, ListResult {..}) = do
-  settings <- readIORef settings'
+set' :: (MonadReader AppState m, MonadIO m, MonadThrow m, MonadFail m, MonadMask m, MonadUnliftIO m)
+     => BrickState
+     -> (Int, ListResult)
+     -> m (Either String ())
+set' bs input@(_, ListResult {..}) = do
+  settings <- liftIO $ readIORef settings'

  let run =
        flip runReaderT settings
@@ -501,7 +510,28 @@ set' _ (_, ListResult {..}) = do
    )
    >>= \case
          VRight _ -> pure $ Right ()
-          VLeft  e -> pure $ Left (prettyShow e)
+          VLeft  e -> case e of
+            (V (NotInstalled tool _)) -> do
+              promptAnswer <- getUserPromptResponse userPrompt
+              case promptAnswer of
+                PromptYes -> do
+                  res <- install' bs input
+                  case res of
+                    (Left err) -> pure $ Left err
+                    (Right _) -> do
+                      logInfo "Setting now..."
+                      set' bs input
+
+                PromptNo -> pure $ Left (prettyShow e)
+              where
+                userPrompt = L.toStrict . B.toLazyText . B.fromString $
+                  "This Version of "
+                  <> show tool
+                  <> " you are trying to set is not installed.\n"
+                  <> "Would you like to install it first? [Y/N]: "
+
+            _ -> pure $ Left (prettyShow e)
+


 del' :: (MonadReader AppState m, MonadIO m, MonadFail m, MonadMask m, MonadUnliftIO m)
@@ -511,7 +541,7 @@ del' :: (MonadReader AppState m, MonadIO m, MonadFail m, MonadMask m, MonadUnlif
 del' _ (_, ListResult {..}) = do
  AppState { ghcupInfo = GHCupInfo { _ghcupDownloads = dls }} <- ask

-  let run = runE @'[NotInstalled]
+  let run = runE @'[NotInstalled, UninstallFailed]

  run (do
      let vi = getVersionInfo lVer lTool dls
--- a/app/ghcup/GHCup/OptParse.hs
+++ b/app/ghcup/GHCup/OptParse.hs
@@ -96,7 +96,7 @@ data Command
  | Config ConfigCommand
  | Whereis WhereisOptions WhereisCommand
 #ifndef DISABLE_UPGRADE
-  | Upgrade UpgradeOpts Bool
+  | Upgrade UpgradeOpts Bool Bool
 #endif
  | ToolRequirements ToolReqOpts
  | ChangeLog ChangeLogOptions
@@ -222,18 +222,18 @@ com =
           (info (List <$> listOpts <**> helper)
                 (progDesc "Show available GHCs and other tools")
           )
-#ifndef DISABLE_UPGRADE
      <> command
           "upgrade"
           (info
             (    (Upgrade <$> upgradeOptsP <*> switch
                    (short 'f' <> long "force" <> help "Force update")
+                    <*> switch
+                    (long "fail-if-shadowed" <> help "Fails after upgrading if the upgraded ghcup binary is shadowed by something else in PATH (useful for CI)")
                  )
             <**> helper
             )
             (progDesc "Upgrade ghcup")
           )
-#endif
      <> command
           "compile"
           (   Compile
--- a/app/ghcup/GHCup/OptParse/ChangeLog.hs
+++ b/app/ghcup/GHCup/OptParse/ChangeLog.hs
@@ -12,9 +12,11 @@ module GHCup.OptParse.ChangeLog where


 import           GHCup.Types
-import           GHCup.Utils.Logger
 import           GHCup.OptParse.Common
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
+import           GHCup.Prelude.Process (exec)

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -34,8 +36,6 @@ import GHCup.Types.Optics
 import GHCup.Utils
 import Data.Versions
 import URI.ByteString (serializeURIRef')
-import GHCup.Utils.Prelude
-import GHCup.Utils.File (exec)
 import Data.Char (toLower)


@@ -58,7 +58,7 @@ data ChangeLogOptions = ChangeLogOptions
    --[ Parsers ]--
    ---------------

-          
+
 changelogP :: Parser ChangeLogOptions
 changelogP =
  (\x y -> ChangeLogOptions x y)
@@ -71,15 +71,16 @@ changelogP =
                "cabal" -> Right Cabal
                "ghcup" -> Right GHCup
                "stack" -> Right Stack
+                "hls"   -> Right HLS
                e       -> Left e
              )
            )
-            (short 't' <> long "tool" <> metavar "<ghc|cabal|ghcup>" <> help
+            (short 't' <> long "tool" <> metavar "<ghc|cabal|hls|ghcup>" <> help
              "Open changelog for given tool (default: ghc)"
              <> completer toolCompleter
            )
          )
-    <*> optional (toolVersionArgument Nothing Nothing)
+    <*> optional (toolVersionTagArgument Nothing Nothing)



@@ -116,7 +117,8 @@ changelog ChangeLogOptions{..} runAppState runLogger = do
      ver' = maybe
        (Right Latest)
        (\case
-          ToolVersion tv -> Left (_tvVersion tv) -- FIXME: ugly sharing of ToolVersion
+          GHCVersion tv  -> Left (_tvVersion tv)
+          ToolVersion tv -> Left tv
          ToolTag     t  -> Right t
        )
        clToolVer
--- a/app/ghcup/GHCup/OptParse/Common.hs
+++ b/app/ghcup/GHCup/OptParse/Common.hs
@@ -16,10 +16,10 @@ import           GHCup.Platform
 import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Utils
-import           GHCup.Utils.File
-import           GHCup.Utils.Logger
-import           GHCup.Utils.MegaParsec
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude
+import           GHCup.Prelude.Process
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.MegaParsec

 import           Control.DeepSeq
 import           Control.Concurrent
@@ -52,7 +52,6 @@ import           Haskus.Utils.Variant.Excepts
 import           Options.Applicative     hiding ( style )
 import           Prelude                 hiding ( appendFile )
 import           Safe
-import           System.Directory
 import           System.Process                  ( readProcess )
 import           System.FilePath
 import           Text.HTML.TagSoup       hiding ( Tag )
@@ -71,20 +70,24 @@ import Control.Exception (evaluate)
    --[ Types ]--
    -------------

-data ToolVersion = ToolVersion GHCTargetVersion -- target is ignored for cabal
+data ToolVersion = GHCVersion GHCTargetVersion
+                 | ToolVersion Version
                 | ToolTag Tag

 -- a superset of ToolVersion
-data SetToolVersion = SetToolVersion GHCTargetVersion
+data SetToolVersion = SetGHCVersion GHCTargetVersion
+                    | SetToolVersion Version
                    | SetToolTag Tag
                    | SetRecommended
                    | SetNext

 prettyToolVer :: ToolVersion -> String
-prettyToolVer (ToolVersion v') = T.unpack $ tVerToText v'
+prettyToolVer (GHCVersion v') = T.unpack $ tVerToText v'
+prettyToolVer (ToolVersion v') = T.unpack $ prettyVer v'
 prettyToolVer (ToolTag t) = show t

 toSetToolVer :: Maybe ToolVersion -> SetToolVersion
+toSetToolVer (Just (GHCVersion v')) = SetGHCVersion v'
 toSetToolVer (Just (ToolVersion v')) = SetToolVersion v'
 toSetToolVer (Just (ToolTag t')) = SetToolTag t'
 toSetToolVer Nothing = SetRecommended
@@ -97,10 +100,9 @@ toSetToolVer Nothing = SetRecommended
    --------------


-- | same as toolVersionParser, except as an argument.
-toolVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser ToolVersion
-toolVersionArgument criteria tool =
-  argument (eitherReader toolVersionEither)
+toolVersionTagArgument :: Maybe ListCriteria -> Maybe Tool -> Parser ToolVersion
+toolVersionTagArgument criteria tool =
+  argument (eitherReader (parser tool))
    (metavar (mv tool)
    <> completer (tagCompleter (fromMaybe GHC tool) [])
    <> foldMap (completer . versionCompleter criteria) tool)
@@ -109,20 +111,19 @@ toolVersionArgument criteria tool =
  mv (Just HLS) = "HLS_VERSION|TAG"
  mv _          = "VERSION|TAG"

+  parser (Just GHC) = ghcVersionTagEither
+  parser Nothing    = ghcVersionTagEither
+  parser _          = toolVersionTagEither

-versionParser :: Parser GHCTargetVersion
-versionParser = option
-  (eitherReader tVersionEither)
-  (short 'v' <> long "version" <> metavar "VERSION" <> help "The target version"
-  )

 versionParser' :: Maybe ListCriteria -> Maybe Tool -> Parser Version
 versionParser' criteria tool = argument
  (eitherReader (first show . version . T.pack))
  (metavar "VERSION"  <> foldMap (completer . versionCompleter criteria) tool)

-versionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser GHCTargetVersion
-versionArgument criteria tool = argument (eitherReader tVersionEither) (metavar "VERSION" <> foldMap (completer . versionCompleter criteria) tool)
+ghcVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser GHCTargetVersion
+ghcVersionArgument criteria tool = argument (eitherReader ghcVersionEither)
+                                            (metavar "VERSION" <> foldMap (completer . versionCompleter criteria) tool)


 -- https://github.com/pcapriotti/optparse-applicative/issues/148
@@ -227,13 +228,19 @@ absolutePathParser f = case isValid f && isAbsolute f of
              False -> Left "Please enter a valid absolute filepath."

 isolateParser :: FilePath -> Either String FilePath
-isolateParser f = case isValid f of
+isolateParser f = case isValid f && isAbsolute f of
              True -> Right $ normalise f
              False -> Left "Please enter a valid filepath for isolate dir."

-toolVersionEither :: String -> Either String ToolVersion
-toolVersionEither s' =
-  second ToolTag (tagEither s') <|> second ToolVersion (tVersionEither s')
+-- this accepts cross prefix
+ghcVersionTagEither :: String -> Either String ToolVersion
+ghcVersionTagEither s' =
+  second ToolTag (tagEither s') <|> second GHCVersion (ghcVersionEither s')
+
+-- this ignores cross prefix
+toolVersionTagEither :: String -> Either String ToolVersion
+toolVersionTagEither s' =
+  second ToolTag (tagEither s') <|> second ToolVersion (toolVersionEither s')

 tagEither :: String -> Either String Tag
 tagEither s' = case fmap toLower s' of
@@ -245,10 +252,14 @@ tagEither s' = case fmap toLower s' of
  other         -> Left $ "Unknown tag " <> other


-tVersionEither :: String -> Either String GHCTargetVersion
-tVersionEither =
+ghcVersionEither :: String -> Either String GHCTargetVersion
+ghcVersionEither =
  first (const "Not a valid version") . MP.parse ghcTargetVerP "" . T.pack

+toolVersionEither :: String -> Either String Version
+toolVersionEither =
+  first (const "Not a valid version") . MP.parse version' "" . T.pack
+

 toolParser :: String -> Either String Tool
 toolParser s' | t == T.pack "ghc"   = Right GHC
@@ -441,9 +452,11 @@ tagCompleter tool add = listIOCompleter $ do
      pure $ nub $ (add ++) $ fmap tagToString allTags
    VLeft _ -> pure  (nub $ ["recommended", "latest"] ++ add)

-
 versionCompleter :: Maybe ListCriteria -> Tool -> Completer
-versionCompleter criteria tool = listIOCompleter $ do
+versionCompleter criteria tool = versionCompleter' criteria tool (const True)
+
+versionCompleter' :: Maybe ListCriteria -> Tool -> (Version -> Bool) -> Completer
+versionCompleter' criteria tool filter' = listIOCompleter $ do
  dirs' <- liftIO getAllDirs
  let loggerConfig = LoggerConfig
        { lcPrintDebug   = False
@@ -472,7 +485,7 @@ versionCompleter criteria tool = listIOCompleter $ do
          runEnv = flip runReaderT appState

      installedVersions <- runEnv $ listVersions (Just tool) criteria
-      return $ T.unpack . prettyVer . lVer <$> installedVersions
+      return $ fmap (T.unpack . prettyVer) . filter filter' . fmap lVer $ installedVersions


 toolDlCompleter :: Tool -> Completer
@@ -664,7 +677,7 @@ fromVersion' SetRecommended tool = do
  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
  bimap mkTVer Just <$> getRecommended dls tool
    ?? TagNotFound Recommended tool
-fromVersion' (SetToolVersion v) tool = do
+fromVersion' (SetGHCVersion v) tool = do
  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
  let vi = getVersionInfo (_tvVersion v) tool dls
  case pvp $ prettyVer (_tvVersion v) of -- need to be strict here
@@ -676,6 +689,18 @@ fromVersion' (SetToolVersion v) tool = do
          when (v' /= _tvVersion v) $ lift $ logWarn ("Assuming you meant version " <> prettyVer v')
          pure (GHCTargetVersion (_tvTarget v) v', Just vi')
        Nothing -> pure (v, vi)
+fromVersion' (SetToolVersion v) tool = do
+  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
+  let vi = getVersionInfo v tool dls
+  case pvp $ prettyVer v of -- need to be strict here
+    Left _ -> pure (mkTVer v, vi)
+    Right pvpIn ->
+      lift (getLatestToolFor tool pvpIn dls) >>= \case
+        Just (pvp_, vi') -> do
+          v' <- lift $ pvpToVersion pvp_ ""
+          when (v' /= v) $ lift $ logWarn ("Assuming you meant version " <> prettyVer v')
+          pure (GHCTargetVersion mempty v', Just vi')
+        Nothing -> pure (mkTVer v, vi)
 fromVersion' (SetToolTag Latest) tool = do
  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
  bimap mkTVer Just <$> getLatest dls tool ?? TagNotFound Latest tool
--- a/app/ghcup/GHCup/OptParse/Compile.hs
+++ b/app/ghcup/GHCup/OptParse/Compile.hs
@@ -12,14 +12,15 @@ module GHCup.OptParse.Compile where


 import           GHCup
+import qualified GHCup.GHC as GHC
+import qualified GHCup.HLS as HLS
 import           GHCup.Errors
-import           GHCup.Utils.File
 import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Utils
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
 import           GHCup.OptParse.Common
-import           GHCup.Utils.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -31,7 +32,8 @@ import           Control.Monad.Trans.Resource
 import           Data.Bifunctor
 import           Data.Functor
 import           Data.Maybe
-import           Data.Versions                  ( Version, prettyVer, version )
+import           Data.Versions                  ( Version, prettyVer, version, pvp )
+import qualified Data.Versions as V
 import           Data.Text                      ( Text )
 import           Haskus.Utils.Variant.Excepts
 import           Options.Applicative     hiding ( style )
@@ -42,7 +44,7 @@ import           Text.PrettyPrint.HughesPJClass ( prettyShow )

 import           URI.ByteString          hiding ( uriParser )
 import qualified Data.Text                     as T
-import Control.Exception.Safe (MonadMask)
+import Control.Exception.Safe (MonadMask, displayException)
 import System.FilePath (isPathSeparator)
 import Text.Read (readEither)

@@ -65,7 +67,7 @@ data CompileCommand = CompileGHC GHCCompileOptions


 data GHCCompileOptions = GHCCompileOptions
-  { targetGhc    :: Either Version GitBranch
+  { targetGhc    :: GHC.GHCVer Version
  , bootstrapGhc :: Either Version FilePath
  , jobs         :: Maybe Int
  , buildConfig  :: Maybe FilePath
@@ -79,11 +81,13 @@ data GHCCompileOptions = GHCCompileOptions
  , isolateDir   :: Maybe FilePath
  }

+
 data HLSCompileOptions = HLSCompileOptions
-  { targetHLS    :: Either Version GitBranch
+  { targetHLS    :: HLS.HLSVer
  , jobs         :: Maybe Int
  , setCompile   :: Bool
-  , ovewrwiteVer :: Maybe Version
+  , updateCabal  :: Bool
+  , ovewrwiteVer :: Either Bool Version
  , isolateDir   :: Maybe FilePath
  , cabalProject :: Maybe (Either FilePath URI)
  , cabalProjectLocal :: Maybe URI
@@ -99,7 +103,7 @@ data HLSCompileOptions = HLSCompileOptions
    --[ Parsers ]--
    ---------------

-          
+
 compileP :: Parser CompileCommand
 compileP = subparser
  (  command
@@ -146,20 +150,22 @@ Examples:

  compileHLSFooter = [s|Discussion:
  Compiles and installs the specified HLS version.
-  The last argument is a list of GHC versions to compile for.
+  The --ghc arguments are necessary to specify which GHC version to build for/against.
  These need to be available in PATH prior to compilation.

 Examples:
-  # compile 1.4.0 for ghc 8.10.5 and 8.10.7
-  ghcup compile hls -v 1.4.0 -j 12 --ghc 8.10.5 --ghc 8.10.7
-  # compile from master for ghc 8.10.7, linking everything dynamically
-  ghcup compile hls -g master -j 12 --ghc 8.10.7 -- --ghc-options='-dynamic'|]
+  # compile 1.7.0.0 from hackage for 8.10.7, running 'cabal update' before the build
+  ghcup compile hls --version 1.7.0.0 --ghc 8.10.7 --cabal-update
+  # compile from master for ghc 9.2.3 using 'git describe' to name the binary and ignore the pinned index state
+  ghcup compile hls -g master --git-describe-version --ghc 9.2.3 -- --index-state=@(date '+%s')
+  # compile a specific commit for ghc 9.2.3 and set a specifc version for the binary name
+  ghcup compile hls -g a32db0b -o 1.7.0.0-p1 --ghc 9.2.3|]


 ghcCompileOpts :: Parser GHCCompileOptions
 ghcCompileOpts =
  GHCCompileOptions
-    <$> ((Left <$> option
+    <$> ((GHC.SourceDist <$> option
          (eitherReader
            (first (const "Not a valid version") . version . T.pack)
          )
@@ -168,7 +174,7 @@ ghcCompileOpts =
            <> (completer $ versionCompleter Nothing GHC)
          )
          ) <|>
-          (Right <$> (GitBranch <$> option
+          (GHC.GitDist <$> (GitBranch <$> option
          str
          (short 'g' <> long "git-ref" <> metavar "GIT_REFERENCE" <> help
            "The git commit/branch/ref to build from"
@@ -177,7 +183,18 @@ ghcCompileOpts =
            short 'r' <> long "repository" <> metavar "GIT_REPOSITORY" <> help "The git repository to build from (defaults to GHC upstream)"
            <> completer (gitFileUri ["https://gitlab.haskell.org/ghc/ghc.git"])
            ))
-          )))
+          ))
+          <|>
+          (
+           GHC.RemoteDist <$> (option
+            (eitherReader uriParser)
+            (long "remote-source-dist" <> metavar "URI" <> help
+              "URI (https/http/file) to a GHC source distribution"
+              <> completer fileUri
+            )
+          )
+          )
+          )
    <*> option
          (eitherReader
            (\x ->
@@ -233,7 +250,7 @@ ghcCompileOpts =
              "Build cross-compiler for this platform"
            )
          )
-    <*> many (argument str (metavar "CONFIGURE_ARGS" <> help "Additional arguments to configure, prefix with '-- ' (longopts)"))
+    <*> many (argument str (metavar "CONFIGURE_ARGS" <> help "Additional arguments to compile configure, prefix with '-- ' (longopts)"))
    <*> fmap (fromMaybe False) (invertableSwitch "set" Nothing False (help "Set as active version after install"))
    <*> optional
          (option
@@ -269,24 +286,46 @@ ghcCompileOpts =
 hlsCompileOpts :: Parser HLSCompileOptions
 hlsCompileOpts =
  HLSCompileOptions
-    <$> ((Left <$> option
+    <$> ((HLS.HackageDist <$> option
          (eitherReader
-            (first (const "Not a valid version") . version . T.pack)
+            ((>>= first displayException . V.version . V.prettyPVP) . first (const "Not a valid PVP version") . pvp . T.pack)
          )
          (short 'v' <> long "version" <> metavar "VERSION" <> help
-            "The tool version to compile"
-            <> (completer $ versionCompleter Nothing HLS)
+            "The version to compile (pulled from hackage)"
+            <> (completer $ versionCompleter' Nothing HLS (either (const False) (const True) . V.pvp . V.prettyVer))
          )
-          ) <|>
-          (Right <$> (GitBranch <$> option
+          )
+          <|>
+          (HLS.GitDist <$> (GitBranch <$> option
          str
          (short 'g' <> long "git-ref" <> metavar "GIT_REFERENCE" <> help
-            "The git commit/branch/ref to build from"
+            "The git commit/branch/ref to build from (accepts anything 'git checkout' accepts)"
          ) <*>
          optional (option str (short 'r' <> long "repository" <> metavar "GIT_REPOSITORY" <> help "The git repository to build from (defaults to HLS upstream)"
            <> completer (gitFileUri ["https://github.com/haskell/haskell-language-server.git"])
          ))
-          )))
+          ))
+          <|>
+          (HLS.SourceDist <$> (option
+            (eitherReader
+              (first (const "Not a valid version") . version . T.pack)
+            )
+          (long "source-dist" <> metavar "VERSION" <> help
+            "The version to compile (pulled from packaged git sources)"
+            <> (completer $ versionCompleter Nothing HLS)
+          )
+          ))
+          <|>
+          (
+           HLS.RemoteDist <$> (option
+            (eitherReader uriParser)
+            (long "remote-source-dist" <> metavar "URI" <> help
+              "URI (https/http/file) to a HLS source distribution"
+              <> completer fileUri
+            )
+          )
+          )
+          )
    <*> optional
          (option
            (eitherReader (readEither @Int))
@@ -296,8 +335,10 @@ hlsCompileOpts =
            )
          )
    <*> fmap (fromMaybe True) (invertableSwitch "set" Nothing True (help "Don't set as active version after install"))
-    <*> optional
-          (option
+    <*> switch (long "cabal-update" <> help "Run 'cabal update' before the build")
+    <*>
+         (
+          (Right <$> option
            (eitherReader
              (first (const "Not a valid version") . version . T.pack)
            )
@@ -306,6 +347,14 @@ hlsCompileOpts =
            <> (completer $ versionCompleter Nothing HLS)
            )
          )
+          <|>
+          (Left <$> (switch
+                      (long "git-describe-version"
+                         <> help "Use the output of 'git describe' (if building from git) as the VERSION component of the installed binary."
+                      )
+                    )
+          )
+          )
    <*> optional
          (option
            (eitherReader isolateParser)
@@ -352,7 +401,7 @@ hlsCompileOpts =
          )
        )
    <*> some (
-          option (eitherReader toolVersionEither)
+          option (eitherReader ghcVersionTagEither)
            (  long "ghc" <> metavar "GHC_VERSION|TAG" <> help "For which GHC version to compile for (can be specified multiple times)"
            <> completer (tagCompleter GHC [])
            <> completer (versionCompleter Nothing GHC))
@@ -388,6 +437,8 @@ type GHCEffects = '[ AlreadyInstalled
                  , ProcessError
                  , CopyError
                  , BuildFailed
+                  , UninstallFailed
+                  , MergeFileTreeError
                  ]
 type HLSEffects = '[ AlreadyInstalled
                  , BuildFailed
@@ -406,6 +457,8 @@ type HLSEffects = '[ AlreadyInstalled
                  , NotInstalled
                  , DirNotEmpty
                  , ArchiveResult
+                  , UninstallFailed
+                  , MergeFileTreeError
                  ]


@@ -454,7 +507,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
    (CompileHLS HLSCompileOptions { .. }) -> do
      runCompileHLS runAppState (do
        case targetHLS of
-          Left targetVer -> do
+          HLS.SourceDist targetVer -> do
            GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
            let vi = getVersionInfo targetVer HLS dls
            forM_ (_viPreCompile =<< vi) $ \msg -> do
@@ -462,16 +515,17 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
              lift $ logInfo
                "...waiting for 5 seconds, you can still abort..."
              liftIO $ threadDelay 5000000 -- for compilation, give the user a sec to intervene
-          Right _ -> pure ()
+          _ -> pure ()
        ghcs <- liftE $ forM targetGHCs (\ghc -> fmap (_tvVersion . fst) . fromVersion (Just ghc) $ GHC)
        targetVer <- liftE $ compileHLS
                    targetHLS
                    ghcs
                    jobs
                    ovewrwiteVer
-                    isolateDir
+                    (maybe GHCupInternal IsolateDir isolateDir)
                    cabalProject
                    cabalProjectLocal
+                    updateCabal
                    patches
                    cabalArgs
        GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
@@ -492,7 +546,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                case keepDirs settings of
                  Never -> runLogger $ logError $ T.pack $ prettyShow err
                  _ -> runLogger (logError $ T.pack (prettyShow err) <> "\n" <>
-                        "Check the logs at " <> T.pack logsDir <> " and the build directory "
+                        "Check the logs at " <> T.pack (fromGHCupPath logsDir) <> " and the build directory "
                        <> T.pack tmpdir <> " for more clues." <> "\n" <>
                        "Make sure to clean up " <> T.pack tmpdir <> " afterwards.")
                pure $ ExitFailure 9
@@ -505,7 +559,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
    (CompileGHC GHCCompileOptions {..}) ->
      runCompileGHC runAppState (do
        case targetGhc of
-          Left targetVer -> do
+          GHC.SourceDist targetVer -> do
            GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
            let vi = getVersionInfo targetVer GHC dls
            forM_ (_viPreCompile =<< vi) $ \msg -> do
@@ -513,9 +567,12 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
              lift $ logInfo
                "...waiting for 5 seconds, you can still abort..."
              liftIO $ threadDelay 5000000 -- for compilation, give the user a sec to intervene
-          Right _ -> pure ()
+          _ -> pure ()
        targetVer <- liftE $ compileGHC
-                    (first (GHCTargetVersion crossTarget) targetGhc)
+                    ((\case
+                        GHC.SourceDist v -> GHC.SourceDist $ GHCTargetVersion crossTarget v
+                        GHC.GitDist g -> GHC.GitDist g
+                        GHC.RemoteDist r -> GHC.RemoteDist r) targetGhc)
                    ovewrwiteVer
                    bootstrapGhc
                    jobs
@@ -524,7 +581,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                    addConfArgs
                    buildFlavour
                    hadrian
-                    isolateDir
+                    (maybe GHCupInternal IsolateDir isolateDir)
        GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
        let vi = getVersionInfo (_tvVersion targetVer) GHC dls
        when setCompile $ void $ liftE $
@@ -541,17 +598,17 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                pure ExitSuccess
              VLeft (V (AlreadyInstalled _ v)) -> do
                runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+                  "GHC ver " <> prettyVer v <> " already installed, remove it first to reinstall"
                pure ExitSuccess
              VLeft (V (DirNotEmpty fp)) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                pure $ ExitFailure 3
              VLeft err@(V (BuildFailed tmpdir _)) -> do
                case keepDirs settings of
                  Never -> runLogger $ logError $ T.pack $ prettyShow err
                  _ -> runLogger (logError $ T.pack (prettyShow err) <> "\n" <>
-                        "Check the logs at " <> T.pack logsDir <> " and the build directory "
+                        "Check the logs at " <> T.pack (fromGHCupPath logsDir) <> " and the build directory "
                        <> T.pack tmpdir <> " for more clues." <> "\n" <>
                        "Make sure to clean up " <> T.pack tmpdir <> " afterwards.")
                pure $ ExitFailure 9
--- a/app/ghcup/GHCup/OptParse/Config.hs
+++ b/app/ghcup/GHCup/OptParse/Config.hs
@@ -7,7 +7,6 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ExplicitForAll #-}

 module GHCup.OptParse.Config where

@@ -15,9 +14,9 @@ module GHCup.OptParse.Config where
 import           GHCup.Errors
 import           GHCup.Types
 import           GHCup.Utils
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
 import           GHCup.OptParse.Common

 #if !MIN_VERSION_base(4,13,0)
--- a/app/ghcup/GHCup/OptParse/DInfo.hs
+++ b/app/ghcup/GHCup/OptParse/DInfo.hs
@@ -17,9 +17,10 @@ import           GHCup
 import           GHCup.Errors
 import           GHCup.Version
 import           GHCup.Types
-import           GHCup.Utils.Prelude
 import           GHCup.Utils.Dirs
-import           GHCup.Utils.Logger
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.Process

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -36,7 +37,6 @@ import           Text.PrettyPrint.HughesPJClass ( prettyShow )

 import qualified Data.Text                     as T
 import Control.Exception.Safe (MonadMask)
-import GHCup.Utils.File
 import Language.Haskell.TH


--- a/app/ghcup/GHCup/OptParse/GC.hs
+++ b/app/ghcup/GHCup/OptParse/GC.hs
@@ -14,8 +14,8 @@ module GHCup.OptParse.GC where
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -56,26 +56,26 @@ data GCOptions = GCOptions
    --[ Parsers ]--
    ---------------

-          
+
 gcP :: Parser GCOptions
 gcP =
  GCOptions
-  <$> 
+  <$>
    switch
      (short 'o' <> long "ghc-old" <> help "Remove GHC versions marked as 'old'")
-  <*> 
+  <*>
    switch
      (short 'p' <> long "profiling-libs" <> help "Remove profiling libs of GHC versions")
-  <*> 
+  <*>
    switch
      (short 's' <> long "share-dir" <> help "Remove GHC share directories (documentation)")
-  <*> 
+  <*>
    switch
      (short 'h' <> long "hls-no-ghc" <> help "Remove HLS versions that don't have a corresponding installed GHC version")
-  <*> 
+  <*>
    switch
      (short 'c' <> long "cache" <> help "GC the GHCup cache")
-  <*> 
+  <*>
    switch
      (short 't' <> long "tmpdirs" <> help "Remove tmpdir leftovers")

@@ -98,7 +98,7 @@ gcFooter = [s|Discussion:
    ---------------------------


-type GCEffects = '[ NotInstalled ]
+type GCEffects = '[ NotInstalled, UninstallFailed ]


 runGC :: MonadUnliftIO m
@@ -129,7 +129,7 @@ gc :: ( Monad m
   -> (ReaderT LeanAppState m () -> m ())
   -> m ExitCode
 gc GCOptions{..} runAppState runLogger = runGC runAppState (do
-  when gcOldGHC rmOldGHC
+  when gcOldGHC (liftE rmOldGHC)
  lift $ when gcProfilingLibs rmProfilingLibs
  lift $ when gcShareDir rmShareDir
  liftE $ when gcHLSNoGHC rmHLSNoGHC
--- a/app/ghcup/GHCup/OptParse/Install.hs
+++ b/app/ghcup/GHCup/OptParse/Install.hs
@@ -7,6 +7,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE DuplicateRecordFields #-}
 {-# LANGUAGE ViewPatterns      #-}
+{-# LANGUAGE TypeOperators     #-}

 module GHCup.OptParse.Install where

@@ -18,8 +19,10 @@ import           GHCup.OptParse.Common
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Utils.Dirs
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 import           Codec.Archive
 #if !MIN_VERSION_base(4,13,0)
@@ -30,7 +33,6 @@ import           Control.Monad.Trans.Resource
 import           Data.Either
 import           Data.Functor
 import           Data.Maybe
-import           Data.Versions           hiding ( str )
 import           Haskus.Utils.Variant.Excepts
 import           Options.Applicative     hiding ( style )
 import           Options.Applicative.Help.Pretty ( text )
@@ -69,6 +71,7 @@ data InstallOptions = InstallOptions
  , instSet      :: Bool
  , isolateDir   :: Maybe FilePath
  , forceInstall :: Bool
+  , addConfArgs  :: [T.Text]
  }


@@ -168,7 +171,7 @@ Examples:
  ghcup install ghc 8.10.2

  # install GHC head fedora bindist
-  ghcup install ghc -u https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27 head|]
+  ghcup install ghc -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head|]


 installOpts :: Maybe Tool -> Parser InstallOptions
@@ -193,7 +196,7 @@ installOpts tool =
                      <> completer (toolDlCompleter (fromMaybe GHC tool))
                    )
                  )
-            <*> (Just <$> toolVersionArgument Nothing tool)
+            <*> (Just <$> toolVersionTagArgument Nothing tool)
            )
        <|> pure (Nothing, Nothing)
        )
@@ -210,13 +213,14 @@ installOpts tool =
           )
          )
    <*> switch
-          (short 'f' <> long "force" <> help "Force install")
+          (short 'f' <> long "force" <> help "Force install (THIS IS UNSAFE, only use it in Dockerfiles or CI)")
+    <*> many (argument str (metavar "CONFIGURE_ARGS" <> help "Additional arguments to bindist configure, prefix with '-- ' (longopts)"))
 where
  setDefault = case tool of
    Nothing  -> False
    Just GHC -> False
    Just _   -> True
-          
+



@@ -257,48 +261,9 @@ type InstallEffects = '[ AlreadyInstalled
                       , NoToolVersionSet
                       , FileAlreadyExistsError
                       , ProcessError
-
-                       , (AlreadyInstalled, ())
-                       , (UnknownArchive, ())
-                       , (ArchiveResult, ())
-                       , (FileDoesNotExistError, ())
-                       , (CopyError, ())
-                       , (NotInstalled, ())
-                       , (DirNotEmpty, ())
-                       , (NoDownload, ())
-                       , (NotInstalled, ())
-                       , (BuildFailed, ())
-                       , (TagNotFound, ())
-                       , (DigestError, ())
-                       , (GPGError, ())
-                       , (DownloadFailed, ())
-                       , (TarDirDoesNotExist, ())
-                       , (NextVerNotFound, ())
-                       , (NoToolVersionSet, ())
-                       , (FileAlreadyExistsError, ())
-                       , (ProcessError, ())
-
-                       , (AlreadyInstalled, NotInstalled)
-                       , (UnknownArchive, NotInstalled)
-                       , (ArchiveResult, NotInstalled)
-                       , (FileDoesNotExistError, NotInstalled)
-                       , (CopyError, NotInstalled)
-                       , (NotInstalled, NotInstalled)
-                       , (DirNotEmpty, NotInstalled)
-                       , (NoDownload, NotInstalled)
-                       , (NotInstalled, NotInstalled)
-                       , (BuildFailed, NotInstalled)
-                       , (TagNotFound, NotInstalled)
-                       , (DigestError, NotInstalled)
-                       , (GPGError, NotInstalled)
-                       , (DownloadFailed, NotInstalled)
-                       , (TarDirDoesNotExist, NotInstalled)
-                       , (NextVerNotFound, NotInstalled)
-                       , (NoToolVersionSet, NotInstalled)
-                       , (FileAlreadyExistsError, NotInstalled)
-                       , (ProcessError, NotInstalled)
-
-                       , ((), NotInstalled)
+                       , UninstallFailed
+                       , MergeFileTreeError
+                       , InstallSetError
                       ]


@@ -313,52 +278,27 @@ runInstTool appstate' mInstPlatform =
    @InstallEffects


-type InstallGHCEffects = '[ TagNotFound
-                          , NextVerNotFound
-                          , NoToolVersionSet
+type InstallGHCEffects = '[ AlreadyInstalled
+                          , ArchiveResult
                          , BuildFailed
+                          , CopyError
+                          , DigestError
                          , DirNotEmpty
-                          , AlreadyInstalled
-
-                          , (AlreadyInstalled, NotInstalled)
-                          , (UnknownArchive, NotInstalled)
-                          , (ArchiveResult, NotInstalled)
-                          , (FileDoesNotExistError, NotInstalled)
-                          , (CopyError, NotInstalled)
-                          , (NotInstalled, NotInstalled)
-                          , (DirNotEmpty, NotInstalled)
-                          , (NoDownload, NotInstalled)
-                          , (BuildFailed, NotInstalled)
-                          , (TagNotFound, NotInstalled)
-                          , (DigestError, NotInstalled)
-                          , (GPGError, NotInstalled)
-                          , (DownloadFailed, NotInstalled)
-                          , (TarDirDoesNotExist, NotInstalled)
-                          , (NextVerNotFound, NotInstalled)
-                          , (NoToolVersionSet, NotInstalled)
-                          , (FileAlreadyExistsError, NotInstalled)
-                          , (ProcessError, NotInstalled)
-
-                          , (AlreadyInstalled, ())
-                          , (UnknownArchive, ())
-                          , (ArchiveResult, ())
-                          , (FileDoesNotExistError, ())
-                          , (CopyError, ())
-                          , (NotInstalled, ())
-                          , (DirNotEmpty, ())
-                          , (NoDownload, ())
-                          , (BuildFailed, ())
-                          , (TagNotFound, ())
-                          , (DigestError, ())
-                          , (GPGError, ())
-                          , (DownloadFailed, ())
-                          , (TarDirDoesNotExist, ())
-                          , (NextVerNotFound, ())
-                          , (NoToolVersionSet, ())
-                          , (FileAlreadyExistsError, ())
-                          , (ProcessError, ())
-
-                          , ((), NotInstalled)
+                          , DownloadFailed
+                          , FileAlreadyExistsError
+                          , FileDoesNotExistError
+                          , GPGError
+                          , MergeFileTreeError
+                          , NextVerNotFound
+                          , NoDownload
+                          , NoToolVersionSet
+                          , NotInstalled
+                          , ProcessError
+                          , TagNotFound
+                          , TarDirDoesNotExist
+                          , UninstallFailed
+                          , UnknownArchive
+                          , InstallSetError
                          ]

 runInstGHC :: AppState
@@ -393,23 +333,25 @@ install installCommand settings getAppState' runLogger = case installCommand of
    (case instBindist of
       Nothing -> runInstGHC s' instPlatform $ do
         (v, vi) <- liftE $ fromVersion instVer GHC
-         void $ liftE $ sequenceE (installGHCBin
+         liftE $ runBothE' (installGHCBin
                     (_tvVersion v)
-                     isolateDir
+                     (maybe GHCupInternal IsolateDir isolateDir)
                     forceInstall
+                     addConfArgs
                   )
-                   $ when instSet $ when (isNothing isolateDir) $ void $ setGHC v SetGHCOnly Nothing
+                   $ when instSet $ when (isNothing isolateDir) $ liftE $ void $ setGHC v SetGHCOnly Nothing
         pure vi
       Just uri -> do
         runInstGHC s'{ settings = settings {noVerify = True}} instPlatform $ do
           (v, vi) <- liftE $ fromVersion instVer GHC
-           void $ liftE $ sequenceE (installGHCBindist
+           liftE $ runBothE' (installGHCBindist
                       (DownloadInfo uri (Just $ RegexDir "ghc-.*") "")
                       (_tvVersion v)
-                       isolateDir
+                       (maybe GHCupInternal IsolateDir isolateDir)
                       forceInstall
+                       addConfArgs
                     )
-                     $ when instSet $ when (isNothing isolateDir) $ void $ setGHC v SetGHCOnly Nothing
+                     $ when instSet $ when (isNothing isolateDir) $ liftE $ void $ setGHC v SetGHCOnly Nothing
           pure vi
      )
        >>= \case
@@ -419,43 +361,41 @@ install installCommand settings getAppState' runLogger = case installCommand of
                  runLogger $ logInfo msg
                pure ExitSuccess

-              VLeft (V (AlreadyInstalled _ v, ())) -> do
-                runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+              VLeft e@(V (AlreadyInstalled _ _)) -> do
+                runLogger $ logWarn $ T.pack $ prettyShow e
                pure ExitSuccess
-              VLeft (V (AlreadyInstalled _ v)) -> do
-                runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+              VLeft e@(V (AlreadyInstalled _ _)) -> do
+                runLogger $ logWarn $ T.pack $ prettyShow e
                pure ExitSuccess

              VLeft (V (DirNotEmpty fp)) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                pure $ ExitFailure 3
-              VLeft (V (DirNotEmpty fp, ())) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+              VLeft (V (DirNotEmpty fp)) -> do
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                pure $ ExitFailure 3

              VLeft err@(V (BuildFailed tmpdir _)) -> do
                case keepDirs settings of
                  Never -> runLogger (logError $ T.pack $ prettyShow err)
                  _ -> runLogger (logError $ T.pack (prettyShow err) <> "\n" <>
-                    "Check the logs at " <> T.pack logsDir <> " and the build directory " <> T.pack tmpdir <> " for more clues." <> "\n" <>
+                    "Check the logs at " <> T.pack (fromGHCupPath logsDir) <> " and the build directory " <> T.pack tmpdir <> " for more clues." <> "\n" <>
                    "Make sure to clean up " <> T.pack tmpdir <> " afterwards.")
                pure $ ExitFailure 3
-              VLeft err@(V (BuildFailed tmpdir _, ())) -> do
+              VLeft err@(V (BuildFailed tmpdir _)) -> do
                case keepDirs settings of
                  Never -> runLogger (logError $ T.pack $ prettyShow err)
                  _ -> runLogger (logError $ T.pack (prettyShow err) <> "\n" <>
-                    "Check the logs at " <> T.pack logsDir <> " and the build directory " <> T.pack tmpdir <> " for more clues." <> "\n" <>
+                    "Check the logs at " <> T.pack (fromGHCupPath logsDir) <> " and the build directory " <> T.pack tmpdir <> " for more clues." <> "\n" <>
                    "Make sure to clean up " <> T.pack tmpdir <> " afterwards.")
                pure $ ExitFailure 3

              VLeft e -> do
                runLogger $ do
                  logError $ T.pack $ prettyShow e
-                  logError $ "Also check the logs in " <> T.pack logsDir
+                  logError $ "Also check the logs in " <> T.pack (fromGHCupPath logsDir)
                pure $ ExitFailure 3


@@ -465,21 +405,21 @@ install installCommand settings getAppState' runLogger = case installCommand of
    (case instBindist of
       Nothing -> runInstTool s' instPlatform $ do
         (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Cabal
-         void $ liftE $ sequenceE (installCabalBin
+         liftE $ runBothE' (installCabalBin
                                    v
-                                    isolateDir
+                                    (maybe GHCupInternal IsolateDir isolateDir)
                                    forceInstall
-                                  ) $ when instSet $ when (isNothing isolateDir) $ void $ setCabal v
+                                  ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setCabal v
         pure vi
       Just uri -> do
         runInstTool s'{ settings = settings { noVerify = True}} instPlatform $ do
           (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Cabal
-           void $ liftE $ sequenceE (installCabalBindist
+           liftE $ runBothE' (installCabalBindist
                                      (DownloadInfo uri Nothing "")
                                      v
-                                      isolateDir
+                                      (maybe GHCupInternal IsolateDir isolateDir)
                                      forceInstall
-                                    ) $ when instSet $ when (isNothing isolateDir) $ void $ setCabal v
+                                    ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setCabal v
           pure vi
      )
      >>= \case
@@ -488,26 +428,24 @@ install installCommand settings getAppState' runLogger = case installCommand of
              forM_ (_viPostInstall =<< vi) $ \msg ->
                runLogger $ logInfo msg
              pure ExitSuccess
-            VLeft (V (AlreadyInstalled _ v)) -> do
-              runLogger $ logWarn $
-                "Cabal ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install cabal --force " <> prettyVer v <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install cabal --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
-            VLeft (V (AlreadyInstalled _ v, ())) -> do
-              runLogger $ logWarn $
-                "Cabal ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install cabal --force " <> prettyVer v <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
-            VLeft (V (FileAlreadyExistsError fp, ())) -> do
+            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install cabal --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
            VLeft e -> do
              runLogger $ do
                logError $ T.pack $ prettyShow e
-                logError $ "Also check the logs in " <> T.pack logsDir
+                logError $ "Also check the logs in " <> T.pack (fromGHCupPath logsDir)
              pure $ ExitFailure 4

  installHLS :: InstallOptions -> IO ExitCode
@@ -516,22 +454,22 @@ install installCommand settings getAppState' runLogger = case installCommand of
     (case instBindist of
       Nothing -> runInstTool s' instPlatform $ do
         (_tvVersion -> v, vi) <- liftE $ fromVersion instVer HLS
-         void $ liftE $ sequenceE (installHLSBin
+         liftE $ runBothE' (installHLSBin
                                    v
-                                    isolateDir
+                                    (maybe GHCupInternal IsolateDir isolateDir)
                                    forceInstall
-                                  ) $ when instSet $ when (isNothing isolateDir) $ void $ setHLS v SetHLSOnly Nothing
+                                  ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setHLS v SetHLSOnly Nothing
         pure vi
       Just uri -> do
         runInstTool s'{ settings = settings { noVerify = True}} instPlatform $ do
           (_tvVersion -> v, vi) <- liftE $ fromVersion instVer HLS
           -- TODO: support legacy
-           void $ liftE $ sequenceE (installHLSBindist
+           liftE $ runBothE' (installHLSBindist
                                      (DownloadInfo uri (Just $ RegexDir "haskell-language-server-*") "")
                                      v
-                                      isolateDir
+                                      (maybe GHCupInternal IsolateDir isolateDir)
                                      forceInstall
-                                    ) $ when instSet $ when (isNothing isolateDir) $ void $ setHLS v SetHLSOnly Nothing
+                                    ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setHLS v SetHLSOnly Nothing
           pure vi
      )
      >>= \case
@@ -540,34 +478,24 @@ install installCommand settings getAppState' runLogger = case installCommand of
              forM_ (_viPostInstall =<< vi) $ \msg ->
                runLogger $ logInfo msg
              pure ExitSuccess
-            VLeft (V (AlreadyInstalled _ v)) -> do
-              runLogger $ logWarn $
-                  "HLS ver "
-                <> prettyVer v
-                <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install hls --force "
-                <> prettyVer v
-                <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install hls --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
-            VLeft (V (AlreadyInstalled _ v, ())) -> do
-              runLogger $ logWarn $
-                  "HLS ver "
-                <> prettyVer v
-                <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install hls --force "
-                <> prettyVer v
-                <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
-            VLeft (V (FileAlreadyExistsError fp, ())) -> do
+            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install hls --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
            VLeft e -> do
              runLogger $ do
                logError $ T.pack $ prettyShow e
-                logError $ "Also check the logs in " <> T.pack logsDir
+                logError $ "Also check the logs in " <> T.pack (fromGHCupPath logsDir)
              pure $ ExitFailure 4

  installStack :: InstallOptions -> IO ExitCode
@@ -576,21 +504,21 @@ install installCommand settings getAppState' runLogger = case installCommand of
     (case instBindist of
        Nothing -> runInstTool s' instPlatform $ do
          (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Stack
-          void $ liftE $ sequenceE (installStackBin
+          liftE $ runBothE' (installStackBin
                                     v
-                                     isolateDir
+                                     (maybe GHCupInternal IsolateDir isolateDir)
                                     forceInstall
-                                   ) $ when instSet $ when (isNothing isolateDir) $ void $ setStack v
+                                   ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setStack v
          pure vi
        Just uri -> do
          runInstTool s'{ settings = settings { noVerify = True}} instPlatform $ do
            (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Stack
-            void $ liftE $ sequenceE (installStackBindist
+            liftE $ runBothE' (installStackBindist
                                       (DownloadInfo uri Nothing "")
                                       v
-                                       isolateDir
+                                       (maybe GHCupInternal IsolateDir isolateDir)
                                       forceInstall
-                                     ) $ when instSet $ when (isNothing isolateDir) $ void $ setStack v
+                                     ) $ when instSet $ when (isNothing isolateDir) $ liftE $ setStack v
            pure vi
      )
      >>= \case
@@ -599,25 +527,22 @@ install installCommand settings getAppState' runLogger = case installCommand of
              forM_ (_viPostInstall =<< vi) $ \msg ->
                runLogger $ logInfo msg
              pure ExitSuccess
-            VLeft (V (AlreadyInstalled _ v)) -> do
-              runLogger $ logWarn $
-                "Stack ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install stack --force " <> prettyVer v <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install stack --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
-            VLeft (V (AlreadyInstalled _ v, ())) -> do
-              runLogger $ logWarn $
-                "Stack ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install stack --force " <> prettyVer v <> "'"
+            VLeft e@(V (AlreadyInstalled _ _)) -> do
+              runLogger $ logWarn $ T.pack $ prettyShow e
              pure ExitSuccess
-            VLeft (V (FileAlreadyExistsError fp, ())) -> do
+            VLeft (V (FileAlreadyExistsError fp)) -> do
              runLogger $ logWarn $
                "File " <> T.pack fp <> " already exists. Use 'ghcup install stack --isolate " <> T.pack fp <> " --force ..." <> "' if you want to overwrite."
              pure $ ExitFailure 3
            VLeft e -> do
              runLogger $ do
                logError $ T.pack $ prettyShow e
-                logError $ "Also check the logs in " <> T.pack logsDir
+                logError $ "Also check the logs in " <> T.pack (fromGHCupPath logsDir)
              pure $ ExitFailure 4
-
--- a/app/ghcup/GHCup/OptParse/List.hs
+++ b/app/ghcup/GHCup/OptParse/List.hs
@@ -11,7 +11,7 @@ module GHCup.OptParse.List where


 import           GHCup
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude
 import           GHCup.Types
 import           GHCup.OptParse.Common

--- a/app/ghcup/GHCup/OptParse/Nuke.hs
+++ b/app/ghcup/GHCup/OptParse/Nuke.hs
@@ -14,7 +14,7 @@ module GHCup.OptParse.Nuke where
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.Logger

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -42,7 +42,7 @@ import Control.Concurrent (threadDelay)
    ---------------------------


-type NukeEffects = '[ NotInstalled ]
+type NukeEffects = '[ NotInstalled, UninstallFailed ]


 runNuke :: AppState
--- a/app/ghcup/GHCup/OptParse/Prefetch.hs
+++ b/app/ghcup/GHCup/OptParse/Prefetch.hs
@@ -14,9 +14,10 @@ module GHCup.OptParse.Prefetch where
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
 import           GHCup.OptParse.Common
-import           GHCup.Utils.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -33,7 +34,6 @@ import           Text.PrettyPrint.HughesPJClass ( prettyShow )

 import qualified Data.Text                     as T
 import Control.Exception.Safe (MonadMask)
-import GHCup.Utils.Prelude
 import GHCup.Download (getDownloadsF)


@@ -74,44 +74,44 @@ data PrefetchGHCOptions = PrefetchGHCOptions {
    --[ Parsers ]--
    ---------------

-          
+
 prefetchP :: Parser PrefetchCommand
 prefetchP = subparser
  (  command
      "ghc"
-      (info 
+      (info
        (PrefetchGHC
          <$> (PrefetchGHCOptions
                <$> ( switch (short 's' <> long "source" <> help "Download source tarball instead of bindist") <**> helper )
                <*> optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*>  optional (toolVersionArgument Nothing (Just GHC)) )
+          <*>  optional (toolVersionTagArgument Nothing (Just GHC)) )
        ( progDesc "Download GHC assets for installation")
      )
      <>
     command
      "cabal"
-      (info 
+      (info
        (PrefetchCabal
          <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just Cabal)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just Cabal)) <**> helper ))
        ( progDesc "Download cabal assets for installation")
      )
      <>
     command
      "hls"
-      (info 
+      (info
        (PrefetchHLS
          <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just HLS)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just HLS)) <**> helper ))
        ( progDesc "Download HLS assets for installation")
      )
      <>
     command
      "stack"
-      (info 
+      (info
        (PrefetchStack
          <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just Stack)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just Stack)) <**> helper ))
        ( progDesc "Download stack assets for installation")
      )
      <>
--- a/app/ghcup/GHCup/OptParse/Rm.hs
+++ b/app/ghcup/GHCup/OptParse/Rm.hs
@@ -18,9 +18,9 @@ import           GHCup.Errors
 import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Utils
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
 import           GHCup.OptParse.Common
-import           GHCup.Utils.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -71,7 +71,7 @@ data RmOptions = RmOptions
    --[ Parsers ]--
    ---------------

-          
+
 rmParser :: Parser (Either RmCommand RmOptions)
 rmParser =
  (Left <$> subparser
@@ -103,7 +103,7 @@ rmParser =


 rmOpts :: Maybe Tool -> Parser RmOptions
-rmOpts tool = RmOptions <$> versionArgument (Just ListInstalled) tool
+rmOpts tool = RmOptions <$> ghcVersionArgument (Just ListInstalled) tool



@@ -127,7 +127,7 @@ rmFooter = [s|Discussion:
    ---------------------------


-type RmEffects = '[ NotInstalled ]
+type RmEffects = '[ NotInstalled, UninstallFailed ]


 runRm :: (ReaderT env m (VEither RmEffects a) -> m (VEither RmEffects a))
--- a/app/ghcup/GHCup/OptParse/Run.hs
+++ b/app/ghcup/GHCup/OptParse/Run.hs
@@ -5,19 +5,24 @@
 {-# LANGUAGE RankNTypes        #-}
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE ViewPatterns      #-}
 module GHCup.OptParse.Run where


 import           GHCup
 import           GHCup.Utils
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.File
 import           GHCup.OptParse.Common
 import           GHCup.Errors
 import           GHCup.Types
 import           GHCup.Types.Optics
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+#ifdef IS_WINDOWS
+import           GHCup.Prelude.Process
+import           GHCup.Prelude.Process.Windows ( execNoMinGW )
+#endif
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 import           Control.Exception.Safe         ( MonadMask, MonadCatch )
 #if !MIN_VERSION_base(4,13,0)
@@ -32,7 +37,6 @@ import           Data.List                      ( intercalate )
 import           Haskus.Utils.Variant.Excepts
 import           Options.Applicative     hiding ( style )
 import           Prelude                 hiding ( appendFile )
-import           System.Directory
 import           System.FilePath
 import           System.Environment
 import           System.Exit
@@ -43,6 +47,7 @@ import qualified Data.Text                     as T
 #ifndef IS_WINDOWS
 import qualified System.Posix.Process          as SPP
 #endif
+import Data.Versions ( prettyVer, Version )



@@ -56,11 +61,13 @@ import qualified System.Posix.Process          as SPP
 data RunOptions = RunOptions
  { runAppendPATH :: Bool
  , runInstTool'  :: Bool
+  , runMinGWPath  :: Bool
  , runGHCVer     :: Maybe ToolVersion
  , runCabalVer   :: Maybe ToolVersion
  , runHLSVer     :: Maybe ToolVersion
  , runStackVer   :: Maybe ToolVersion
  , runBinDir     :: Maybe FilePath
+  , runQuick      :: Bool
  , runCOMMAND    :: [String]
  }

@@ -70,8 +77,8 @@ data RunOptions = RunOptions
    --[ Parsers ]--
    ---------------

-          
-    
+
+
 runOpts :: Parser RunOptions
 runOpts =
  RunOptions
@@ -79,9 +86,11 @@ runOpts =
          (short 'a' <> long "append" <> help "Append bin/ dir to PATH instead of prepending (this means that e.g. a system installation may take precedence)")
    <*> switch
          (short 'i' <> long "install" <> help "Install the tool, if missing")
+    <*> switch
+          (short 'm' <> long "mingw-path" <> help "On windows, add mingw64 PATHs to environment (does nothing on unix)")
    <*> optional
          (option
-            (eitherReader toolVersionEither)
+            (eitherReader ghcVersionTagEither)
            (metavar "GHC_VERSION" <> long "ghc" <> help "The ghc version"
            <> completer (tagCompleter GHC [])
            <> (completer $ versionCompleter Nothing GHC)
@@ -89,7 +98,7 @@ runOpts =
          )
    <*> optional
          (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
            (metavar "CABAL_VERSION" <> long "cabal" <> help "The cabal version"
            <> completer (tagCompleter Cabal [])
            <> (completer $ versionCompleter Nothing Cabal)
@@ -97,7 +106,7 @@ runOpts =
          )
    <*> optional
          (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
            (metavar "HLS_VERSION" <> long "hls" <> help "The HLS version"
            <> completer (tagCompleter HLS [])
            <> (completer $ versionCompleter Nothing HLS)
@@ -105,7 +114,7 @@ runOpts =
          )
    <*> optional
          (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
            (metavar "STACK_VERSION" <> long "stack" <> help "The stack version"
            <> completer (tagCompleter Stack [])
            <> (completer $ versionCompleter Nothing Stack)
@@ -121,6 +130,8 @@ runOpts =
           <> completer (bashCompleter "directory")
           )
          )
+    <*> switch
+          (short 'q' <> long "quick" <> help "Avoid any expensive work (such as downloads, version/tag resolution etc.). Disables --install.")
    <*> many (argument str (metavar "COMMAND" <> help "The command to run, with arguments (use longopts --). If omitted, just prints the created bin/ dir to stdout and exits."))
          

@@ -173,6 +184,8 @@ type RunEffects = '[ AlreadyInstalled
                   , NoToolVersionSet
                   , FileAlreadyExistsError
                   , ProcessError
+                   , UninstallFailed
+                   , MergeFileTreeError
                   ]

 runLeanRUN :: (MonadUnliftIO m, MonadIO m)
@@ -206,7 +219,7 @@ runRUN appState action' = do



-run :: forall m. 
+run :: forall m .
       ( MonadFail m
       , MonadMask m
       , MonadCatch m
@@ -219,29 +232,19 @@ run :: forall m.
   -> (ReaderT LeanAppState m () -> m ())
   -> m ExitCode
 run RunOptions{..} runAppState leanAppstate runLogger = do
-   r <- if or (fmap (maybe False isToolTag) [runGHCVer, runCabalVer, runHLSVer, runStackVer]) || runInstTool'
+   r <- if not runQuick
        then runRUN runAppState $ do
         toolchain <- liftE resolveToolchainFull
-         tmp <- case runBinDir of
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
+
+         -- oh dear
+         r <- lift ask
+         tmp <- lift . lift . lift . flip runReaderT (fromAppState r) $ createTmpDir toolchain
+
         liftE $ installToolChainFull toolchain tmp
         pure tmp
        else runLeanRUN leanAppstate $ do
         toolchain <- resolveToolchain
-         tmp <- case runBinDir of
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
+         tmp <- lift $ createTmpDir toolchain
         liftE $ installToolChain toolchain tmp
         pure tmp
   case r of
@@ -256,7 +259,9 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
               void $ liftIO $ SPP.executeFile cmd True args (Just newEnv)
               pure ExitSuccess
 #else
-               r' <- runLeanRUN leanAppstate $ liftE $ lEM @_ @'[ProcessError] $ exec cmd args Nothing (Just newEnv)
+               r' <- if runMinGWPath
+                     then runLeanRUN leanAppstate $ liftE $ lEM @_ @'[ProcessError] $ exec cmd args Nothing (Just newEnv)
+                     else runLeanRUN leanAppstate $ liftE $ lEM @_ @'[ProcessError] $ execNoMinGW cmd args Nothing (Just newEnv)
               case r' of
                 VRight _ -> pure ExitSuccess
                 VLeft e -> do
@@ -269,10 +274,6 @@ run RunOptions{..} runAppState leanAppstate runLogger = do

  where

-   isToolTag :: ToolVersion -> Bool
-   isToolTag (ToolTag _) = True
-   isToolTag _           = False
-
   -- TODO: doesn't work for cross
   resolveToolchainFull :: ( MonadFail m
                           , MonadThrow m
@@ -290,29 +291,33 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
           pure v
         cabalVer <- forM runCabalVer $ \ver -> do
           (v, _) <- liftE $ fromVersion (Just ver) Cabal
-           pure v
+           pure (_tvVersion v)
         hlsVer <- forM runHLSVer $ \ver -> do
           (v, _) <- liftE $ fromVersion (Just ver) HLS
-           pure v
+           pure (_tvVersion v)
         stackVer <- forM runStackVer $ \ver -> do
           (v, _) <- liftE $ fromVersion (Just ver) Stack
-           pure v
+           pure (_tvVersion v)
         pure Toolchain{..}

   resolveToolchain = do
         ghcVer <- case runGHCVer of
-            Just (ToolVersion v) -> pure $ Just v
+            Just (GHCVersion v) -> pure $ Just v
+            Just (ToolVersion v) -> pure $ Just (mkTVer v)
            Nothing -> pure Nothing
            _ -> fail "Internal error"
         cabalVer <- case runCabalVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
            Just (ToolVersion v) -> pure $ Just v
            Nothing -> pure Nothing
            _ -> fail "Internal error"
         hlsVer <- case runHLSVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
            Just (ToolVersion v) -> pure $ Just v
            Nothing -> pure Nothing
            _ -> fail "Internal error"
         stackVer <- case runStackVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
            Just (ToolVersion v) -> pure $ Just v
            Nothing -> pure Nothing
            _ -> fail "Internal error"
@@ -343,36 +348,47 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
                              , AlreadyInstalled
                              , FileAlreadyExistsError
                              , CopyError
+                              , UninstallFailed
+                              , MergeFileTreeError
                              ] (ResourceT (ReaderT AppState m)) ()
   installToolChainFull Toolchain{..} tmp = do
-         forM_ [(GHC,) <$> ghcVer, (Cabal,) <$> cabalVer, (HLS,) <$> hlsVer, (Stack,) <$> stackVer] $ \mt -> do
-           isInstalled <- maybe (pure False) (\(tool, v) -> lift $ checkIfToolInstalled' tool v) mt
-           case mt of
-             Just (GHC, v) -> do
-               unless isInstalled $ when (runInstTool' && isNothing (_tvTarget v)) $ void $ liftE $ installGHCBin
-                 (_tvVersion v)
-                 Nothing
-                 False
-               setTool GHC v tmp
-             Just (Cabal, v) -> do
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installCabalBin
-                 (_tvVersion v)
-                 Nothing
-                 False
-               setTool Cabal v tmp
-             Just (Stack, v) -> do
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installStackBin
-                 (_tvVersion v)
-                 Nothing
-                 False
-               setTool Stack v tmp
-             Just (HLS, v) -> do
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installHLSBin
-                 (_tvVersion v)
-                 Nothing
-                 False
-               setTool HLS v tmp
-             _ -> pure ()
+         case ghcVer of
+           Just v -> do
+             isInstalled <- lift $ checkIfToolInstalled' GHC v
+             unless isInstalled $ when (runInstTool' && isNothing (_tvTarget v)) $ void $ liftE $ installGHCBin
+               (_tvVersion v)
+               GHCupInternal
+               False
+               []
+             setGHC' v tmp
+           _ -> pure ()
+         case cabalVer of
+           Just v -> do
+             isInstalled <- lift $ checkIfToolInstalled' Cabal (mkTVer v)
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installCabalBin
+               v
+               GHCupInternal
+               False
+             setCabal' v tmp
+           _ -> pure ()
+         case stackVer of
+           Just v -> do
+             isInstalled <- lift $ checkIfToolInstalled' Stack (mkTVer v)
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installStackBin
+               v
+               GHCupInternal
+               False
+             setStack' v tmp
+           _ -> pure ()
+         case hlsVer of
+           Just v -> do
+             isInstalled <- lift $ checkIfToolInstalled' HLS (mkTVer v)
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installHLSBin
+               v
+               GHCupInternal
+               False
+             setHLS' v tmp
+           _ -> pure ()

   installToolChain :: ( MonadFail m
                       , MonadThrow m
@@ -383,46 +399,47 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
                    -> FilePath
                    -> Excepts '[NotInstalled] (ReaderT LeanAppState m) ()
   installToolChain Toolchain{..} tmp = do
-         forM_ [(GHC,) <$> ghcVer, (Cabal,) <$> cabalVer, (HLS,) <$> hlsVer, (Stack,) <$> stackVer] $ \mt -> do
-           case mt of
-             Just (GHC, v)   -> setTool GHC v tmp
-             Just (Cabal, v) -> setTool Cabal v tmp
-             Just (Stack, v) -> setTool Stack v tmp
-             Just (HLS, v)   -> setTool HLS v tmp
-             _ -> pure ()
+         case ghcVer of
+           Just v -> setGHC' v tmp
+           _ -> pure ()
+         case cabalVer of
+           Just v -> setCabal' v tmp
+           _ -> pure ()
+         case stackVer of
+           Just v -> setStack' v tmp
+           _ -> pure ()
+         case hlsVer of
+           Just v -> setHLS' v tmp
+           _ -> pure ()

-   setTool tool v tmp =
-      case tool of
-        GHC -> do
+   setGHC' v tmp = do
          void $ liftE $ setGHC v SetGHC_XYZ (Just tmp)
          void $ liftE $ setGHC v SetGHCOnly (Just tmp)
-        Cabal -> do
-          bin  <- liftE $ whereIsTool Cabal v
+   setCabal' v tmp = do
+          bin  <- liftE $ whereIsTool Cabal (mkTVer v)
          cbin <- liftIO $ canonicalizePath bin
          lift $ createLink (relativeSymlink tmp cbin) (tmp </> ("cabal" <.> exeExt))
-        Stack -> do
-          bin  <- liftE $ whereIsTool Stack v
+   setStack' v tmp = do
+          bin  <- liftE $ whereIsTool Stack (mkTVer v)
          cbin <- liftIO $ canonicalizePath bin
          lift $ createLink (relativeSymlink tmp cbin) (tmp </> ("stack" <.> exeExt))
-        HLS -> do
+   setHLS' v tmp = do
          Dirs {..}  <- getDirs
-          let v' = _tvVersion v
-          legacy <- isLegacyHLS v'
+          legacy <- isLegacyHLS v
          if legacy
          then do
            -- TODO: factor this out
-            hlsWrapper <- liftE @_ @'[NotInstalled] $ hlsWrapperBinary v' !? (NotInstalled HLS (mkTVer v'))
+            hlsWrapper <- liftE @_ @'[NotInstalled] $ hlsWrapperBinary v !? (NotInstalled HLS (mkTVer v))
            cw <- liftIO $ canonicalizePath (binDir </> hlsWrapper)
            lift $ createLink (relativeSymlink tmp cw) (tmp </> takeFileName cw)
-            hlsBins <- hlsServerBinaries v' Nothing >>= liftIO . traverse (canonicalizePath . (binDir </>))
+            hlsBins <- hlsServerBinaries v Nothing >>= liftIO . traverse (canonicalizePath . (binDir </>))
            forM_ hlsBins $ \bin ->
              lift $ createLink (relativeSymlink tmp bin) (tmp </> takeFileName bin)
-            liftE $ setHLS (_tvVersion v) SetHLSOnly (Just tmp)
+            liftE $ setHLS v SetHLSOnly (Just tmp)
          else do
-            liftE $ setHLS (_tvVersion v) SetHLS_XYZ (Just tmp)
-            liftE $ setHLS (_tvVersion v) SetHLSOnly (Just tmp)
-        GHCup -> pure ()
-       
+            liftE $ setHLS v SetHLS_XYZ (Just tmp)
+            liftE $ setHLS v SetHLSOnly (Just tmp)
+
   addToPath path = do
    cEnv <- Map.fromList <$> getEnvironment
    let paths          = ["PATH", "Path"]
@@ -434,16 +451,38 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
    liftIO $ setEnv pathVar newPath
    return envWithNewPath

-   predictableTmpDir (Toolchain Nothing Nothing Nothing Nothing) =
-     liftIO (getTemporaryDirectory >>= \tmp -> pure (tmp </> "ghcup-none"))
+   createTmpDir :: ( MonadUnliftIO m
+                   , MonadCatch m
+                   , MonadThrow m
+                   , MonadMask m
+                   , MonadIO m
+                   )
+                => Toolchain
+                -> ReaderT LeanAppState m FilePath
+   createTmpDir toolchain =
+     case runBinDir of
+           Just bindir -> do
+             liftIO $ createDirRecursive' bindir
+             liftIO $ canonicalizePath bindir
+           Nothing -> do
+             d <- predictableTmpDir toolchain
+             liftIO $ createDirRecursive' d
+             liftIO $ canonicalizePath d
+
+   predictableTmpDir :: Monad m
+                     => Toolchain
+                     -> ReaderT LeanAppState m FilePath
+   predictableTmpDir (Toolchain Nothing Nothing Nothing Nothing) = do
+     Dirs { tmpDir } <- getDirs
+     pure (fromGHCupPath tmpDir </> "ghcup-none")
   predictableTmpDir Toolchain{..} = do
-      tmp <- getTemporaryDirectory
-      pure $ tmp
+      Dirs { tmpDir } <- getDirs
+      pure $ fromGHCupPath tmpDir
        </> ("ghcup-" <> intercalate "_"
              (  maybe [] ( (:[]) . ("ghc-"   <>) . T.unpack . tVerToText) ghcVer
-              <> maybe [] ( (:[]) . ("cabal-" <>) . T.unpack . tVerToText) cabalVer
-              <> maybe [] ( (:[]) . ("hls-"   <>) . T.unpack . tVerToText) hlsVer
-              <> maybe [] ( (:[]) . ("stack-" <>) . T.unpack . tVerToText) stackVer
+              <> maybe [] ( (:[]) . ("cabal-" <>) . T.unpack . prettyVer) cabalVer
+              <> maybe [] ( (:[]) . ("hls-"   <>) . T.unpack . prettyVer) hlsVer
+              <> maybe [] ( (:[]) . ("stack-" <>) . T.unpack . prettyVer) stackVer
              )
            )

@@ -457,7 +496,7 @@ run RunOptions{..} runAppState leanAppstate runLogger = do

 data Toolchain = Toolchain
  { ghcVer     :: Maybe GHCTargetVersion
-  , cabalVer   :: Maybe GHCTargetVersion
-  , hlsVer     :: Maybe GHCTargetVersion
-  , stackVer   :: Maybe GHCTargetVersion
-  }
+  , cabalVer   :: Maybe Version
+  , hlsVer     :: Maybe Version
+  , stackVer   :: Maybe Version
+  } deriving Show
--- a/app/ghcup/GHCup/OptParse/Set.hs
+++ b/app/ghcup/GHCup/OptParse/Set.hs
@@ -17,8 +17,8 @@ import           GHCup.OptParse.Common
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -74,7 +74,7 @@ data SetOptions = SetOptions
    --[ Parsers ]--
    ---------------

-          
+
 setParser :: Parser (Either SetCommand SetOptions)
 setParser =
  (Left <$> subparser
@@ -82,7 +82,7 @@ setParser =
          "ghc"
          (   SetGHC
          <$> info
-                (setOpts (Just GHC) <**> helper)
+                (setOpts GHC <**> helper)
                (  progDesc "Set GHC version"
                <> footerDoc (Just $ text setGHCFooter)
                )
@@ -91,7 +91,7 @@ setParser =
           "cabal"
           (   SetCabal
           <$> info
-                 (setOpts (Just Cabal) <**> helper)
+                 (setOpts Cabal <**> helper)
                 (  progDesc "Set Cabal version"
                 <> footerDoc (Just $ text setCabalFooter)
                 )
@@ -100,7 +100,7 @@ setParser =
           "hls"
           (   SetHLS
           <$> info
-                 (setOpts (Just HLS) <**> helper)
+                 (setOpts HLS <**> helper)
                 (  progDesc "Set haskell-language-server version"
                 <> footerDoc (Just $ text setHLSFooter)
                 )
@@ -109,14 +109,14 @@ setParser =
           "stack"
           (   SetStack
           <$> info
-                 (setOpts (Just Stack) <**> helper)
+                 (setOpts Stack <**> helper)
                 (  progDesc "Set stack version"
                 <> footerDoc (Just $ text setStackFooter)
                 )
           )
      )
    )
-    <|> (Right <$> setOpts Nothing)
+    <|> (Right <$> setOpts GHC)
 where
  setGHCFooter :: String
  setGHCFooter = [s|Discussion:
@@ -137,22 +137,25 @@ setParser =
    Sets the the current haskell-language-server version.|]


-setOpts :: Maybe Tool -> Parser SetOptions
+setOpts :: Tool -> Parser SetOptions
 setOpts tool = SetOptions <$>
    (fromMaybe SetRecommended <$>
      optional (setVersionArgument (Just ListInstalled) tool))

-setVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser SetToolVersion
+setVersionArgument :: Maybe ListCriteria -> Tool -> Parser SetToolVersion
 setVersionArgument criteria tool =
  argument (eitherReader setEither)
    (metavar "VERSION|TAG|next"
-    <> completer (tagCompleter (fromMaybe GHC tool) ["next"])
-    <> foldMap (completer . versionCompleter criteria) tool)
+    <> completer (tagCompleter tool ["next"])
+    <> (completer . versionCompleter criteria) tool)
 where
  setEither s' =
        parseSet s'
    <|> second SetToolTag (tagEither s')
-    <|> second SetToolVersion (tVersionEither s')
+    <|> se s'
+  se s' = case tool of
+           GHC -> second SetGHCVersion (ghcVersionEither s')
+           _   -> second SetToolVersion (toolVersionEither s')
  parseSet s' = case fmap toLower s' of
                  "next" -> Right SetNext
                  other  -> Left $ "Unknown tag/version " <> other
@@ -261,9 +264,9 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
  (Right sopts) -> do
    runLogger (logWarn "This is an old-style command for setting GHC. Use 'ghcup set ghc' instead.")
    setGHC' sopts
-  (Left (SetGHC sopts)) -> setGHC' sopts
+  (Left (SetGHC sopts))   -> setGHC'   sopts
  (Left (SetCabal sopts)) -> setCabal' sopts
-  (Left (SetHLS sopts)) -> setHLS' sopts
+  (Left (SetHLS sopts))   -> setHLS'   sopts
  (Left (SetStack sopts)) -> setStack' sopts

 where
@@ -271,7 +274,7 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
          -> m ExitCode
  setGHC' SetOptions{ sToolVer } =
    case sToolVer of
-      (SetToolVersion v) -> runSetGHC runLeanAppState (liftE $ setGHC v SetGHCOnly Nothing >> pure v)
+      (SetGHCVersion v) -> runSetGHC runLeanAppState (liftE $ setGHC v SetGHCOnly Nothing >> pure v)
      _ -> runSetGHC runAppState (do
          v <- liftE $ fst <$> fromVersion' sToolVer GHC
          liftE $ setGHC v SetGHCOnly Nothing
@@ -291,17 +294,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
            -> m ExitCode
  setCabal' SetOptions{ sToolVer } =
    case sToolVer of
-      (SetToolVersion v) -> runSetCabal runLeanAppState (liftE $ setCabal (_tvVersion v) >> pure v)
+      (SetToolVersion v) -> runSetCabal runLeanAppState (liftE $ setCabal v >> pure (mkTVer v))
      _ -> runSetCabal runAppState (do
          v <- liftE $ fst <$> fromVersion' sToolVer Cabal
          liftE $ setCabal (_tvVersion v)
          pure v
        )
      >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
              runLogger
                $ logInfo $
-                    "Cabal " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "Cabal " <> prettyVer (_tvVersion v) <> " successfully set as default version"
              pure ExitSuccess
            VLeft  e -> do
              runLogger $ logError $ T.pack $ prettyShow e
@@ -311,17 +314,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
          -> m ExitCode
  setHLS' SetOptions{ sToolVer } =
    case sToolVer of
-      (SetToolVersion v) -> runSetHLS runLeanAppState (liftE $ setHLS (_tvVersion v) SetHLSOnly Nothing >> pure v)
+      (SetToolVersion v) -> runSetHLS runLeanAppState (liftE $ setHLS v SetHLSOnly Nothing >> pure (mkTVer v))
      _ -> runSetHLS runAppState (do
          v <- liftE $ fst <$> fromVersion' sToolVer HLS
          liftE $ setHLS (_tvVersion v) SetHLSOnly Nothing
          pure v
        )
      >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
              runLogger
                $ logInfo $
-                    "HLS " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "HLS " <> prettyVer (_tvVersion v) <> " successfully set as default version"
              pure ExitSuccess
            VLeft  e -> do
              runLogger $ logError $ T.pack $ prettyShow e
@@ -332,17 +335,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
            -> m ExitCode
  setStack' SetOptions{ sToolVer } =
    case sToolVer of
-      (SetToolVersion v) -> runSetStack runLeanAppState (liftE $ setStack (_tvVersion v) >> pure v)
+      (SetToolVersion v) -> runSetStack runLeanAppState (liftE $ setStack v >> pure (mkTVer v))
      _ -> runSetStack runAppState (do
            v <- liftE $ fst <$> fromVersion' sToolVer Stack
            liftE $ setStack (_tvVersion v)
            pure v
          )
      >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
              runLogger
                $ logInfo $
-                    "Stack " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "Stack " <> prettyVer (_tvVersion v) <> " successfully set as default version"
              pure ExitSuccess
            VLeft  e -> do
              runLogger $ logError $ T.pack $ prettyShow e
--- a/app/ghcup/GHCup/OptParse/ToolRequirements.hs
+++ b/app/ghcup/GHCup/OptParse/ToolRequirements.hs
@@ -11,8 +11,8 @@ module GHCup.OptParse.ToolRequirements where

 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -30,7 +30,7 @@ import qualified Data.Text.IO                  as T
 import Control.Exception.Safe (MonadMask)
 import GHCup.Types.Optics
 import GHCup.Platform
-import GHCup.Utils.Prelude
+import GHCup.Prelude
 import GHCup.Requirements
 import System.IO

--- a/app/ghcup/GHCup/OptParse/UnSet.hs
+++ b/app/ghcup/GHCup/OptParse/UnSet.hs
@@ -16,8 +16,8 @@ module GHCup.OptParse.UnSet where
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
--- a/app/ghcup/GHCup/OptParse/Upgrade.hs
+++ b/app/ghcup/GHCup/OptParse/Upgrade.hs
@@ -14,7 +14,8 @@ module GHCup.OptParse.Upgrade where
 import           GHCup
 import           GHCup.Errors
 import           GHCup.Types
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -59,15 +60,16 @@ data UpgradeOpts = UpgradeInplace
    --[ Parsers ]--
    ---------------

-          
+
 upgradeOptsP :: Parser UpgradeOpts
 upgradeOptsP =
  flag'
      UpgradeInplace
      (short 'i' <> long "inplace" <> help
-        "Upgrade ghcup in-place (wherever it's at)"
+        "Upgrade ghcup in-place"
      )
-    <|> (   UpgradeAt
+    <|>
+      (   UpgradeAt
        <$> option
              str
              (short 't' <> long "target" <> metavar "TARGET_DIR" <> help
@@ -92,6 +94,7 @@ type UpgradeEffects = '[ DigestError
                       , FileDoesNotExistError
                       , CopyError
                       , DownloadFailed
+                       , ToolShadowed
                       ]


@@ -120,18 +123,19 @@ upgrade :: ( Monad m
           )
        => UpgradeOpts
        -> Bool
+        -> Bool
        -> Dirs
        -> (forall a. ReaderT AppState m (VEither UpgradeEffects a) -> m (VEither UpgradeEffects a))
        -> (ReaderT LeanAppState m () -> m ())
        -> m ExitCode
-upgrade uOpts force' Dirs{..} runAppState runLogger = do
+upgrade uOpts force' fatal Dirs{..} runAppState runLogger = do
  target <- case uOpts of
    UpgradeInplace  -> Just <$> liftIO getExecutablePath
    (UpgradeAt p)   -> pure $ Just p
    UpgradeGHCupDir -> pure (Just (binDir </> "ghcup" <> exeExt))

  runUpgrade runAppState (do
-    v' <- liftE $ upgradeGHCup target force'
+    v' <- liftE $ upgradeGHCup target force' fatal
    GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
    pure (v', dls)
    ) >>= \case
--- a/app/ghcup/GHCup/OptParse/Whereis.hs
+++ b/app/ghcup/GHCup/OptParse/Whereis.hs
@@ -17,8 +17,9 @@ import           GHCup
 import           GHCup.Errors
 import           GHCup.OptParse.Common
 import           GHCup.Types
-import           GHCup.Utils.Logger
-import           GHCup.Utils.String.QQ
+import           GHCup.Utils
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -74,14 +75,14 @@ data WhereisOptions = WhereisOptions {
    --[ Parsers ]--
    ---------------

-          
+
 whereisP :: Parser WhereisCommand
 whereisP = subparser
-  (commandGroup "Tools locations:" <> 
+  (commandGroup "Tools locations:" <>
    command
      "ghc"
      (WhereisTool GHC <$> info
-        ( optional (toolVersionArgument Nothing (Just GHC)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just GHC)) <**> helper )
        ( progDesc "Get GHC location"
        <> footerDoc (Just $ text whereisGHCFooter ))
      )
@@ -89,7 +90,7 @@ whereisP = subparser
     command
      "cabal"
      (WhereisTool Cabal <$> info
-        ( optional (toolVersionArgument Nothing (Just Cabal)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just Cabal)) <**> helper )
        ( progDesc "Get cabal location"
        <> footerDoc (Just $ text whereisCabalFooter ))
      )
@@ -97,7 +98,7 @@ whereisP = subparser
     command
      "hls"
      (WhereisTool HLS <$> info
-        ( optional (toolVersionArgument Nothing (Just HLS)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just HLS)) <**> helper )
        ( progDesc "Get HLS location"
        <> footerDoc (Just $ text whereisHLSFooter ))
      )
@@ -105,7 +106,7 @@ whereisP = subparser
     command
      "stack"
      (WhereisTool Stack <$> info
-        ( optional (toolVersionArgument Nothing (Just Stack)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just Stack)) <**> helper )
        ( progDesc "Get stack location"
        <> footerDoc (Just $ text whereisStackFooter ))
      )
@@ -267,7 +268,7 @@ whereis :: ( Monad m
 whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
  Dirs{ .. }  <- runReaderT getDirs leanAppstate
  case (whereisCommand, whereisOptions) of
-    (WhereisTool tool (Just (ToolVersion v)), WhereisOptions{..}) ->
+    (WhereisTool tool (Just (GHCVersion v)), WhereisOptions{..}) ->
      runLeanWhereIs leanAppstate (do
        loc <- liftE $ whereIsTool tool v
        if directory
@@ -281,6 +282,20 @@ whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
              VLeft e -> do
                runLogger $ logError $ T.pack $ prettyShow e
                pure $ ExitFailure 30
+    (WhereisTool tool (Just (ToolVersion v)), WhereisOptions{..}) ->
+      runLeanWhereIs leanAppstate (do
+        loc <- liftE $ whereIsTool tool (mkTVer v)
+        if directory
+        then pure $ takeDirectory loc
+        else pure loc
+        )
+        >>= \case
+              VRight r -> do
+                liftIO $ putStr r
+                pure ExitSuccess
+              VLeft e -> do
+                runLogger $ logError $ T.pack $ prettyShow e
+                pure $ ExitFailure 30

    (WhereisTool tool whereVer, WhereisOptions{..}) -> do
      runWhereIs runAppState (do
@@ -299,7 +314,7 @@ whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
                pure $ ExitFailure 30

    (WhereisBaseDir, _) -> do
-      liftIO $ putStr baseDir
+      liftIO $ putStr $ fromGHCupPath baseDir
      pure ExitSuccess

    (WhereisBinDir, _) -> do
@@ -307,13 +322,13 @@ whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
      pure ExitSuccess

    (WhereisCacheDir, _) -> do
-      liftIO $ putStr cacheDir
+      liftIO $ putStr $ fromGHCupPath cacheDir
      pure ExitSuccess

    (WhereisLogsDir, _) -> do
-      liftIO $ putStr logsDir
+      liftIO $ putStr $ fromGHCupPath logsDir
      pure ExitSuccess

    (WhereisConfDir, _) -> do
-      liftIO $ putStr confDir
+      liftIO $ putStr $ fromGHCupPath confDir
      pure ExitSuccess
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
@@ -14,6 +14,8 @@ module Main where
 import           BrickMain                    ( brickMain )
 #endif

+import qualified GHCup.GHC as GHC
+import qualified GHCup.HLS as HLS
 import           GHCup.OptParse

 import           GHCup.Download
@@ -22,9 +24,9 @@ import           GHCup.Platform
 import           GHCup.Types
 import           GHCup.Types.Optics      hiding ( toolRequirements )
 import           GHCup.Utils
-import           GHCup.Utils.Logger
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.String.QQ
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.String.QQ
 import           GHCup.Version

 import           Cabal.Plan ( findPlanJson, SearchPlanJson(..) )
@@ -141,9 +143,7 @@ main = do
        )
  let listCommands = infoOption
        ("install set rm install-cabal list"
-#ifndef DISABLE_UPGRADE
          <> " upgrade"
-#endif
          <> " compile debug-info tool-requirements changelog"
        )
        (  long "list-commands"
@@ -157,7 +157,6 @@ main = do
  versions. It maintains a self-contained ~/.ghcup directory.

 ENV variables:
-  * TMPDIR: where ghcup does the work (unpacking, building, ...)
  * GHCUP_INSTALL_BASE_PREFIX: the base of ghcup (default: $HOME)
  * GHCUP_USE_XDG_DIRS: set to anything to use XDG style directories

@@ -222,7 +221,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                let s' = AppState settings dirs keybindings ghcupInfo pfreq loggerConfig

                race_ (liftIO $ runReaderT cleanupTrash s')
-                      (threadDelay 5000000 >> runLogger (logWarn $ "Killing cleanup thread (exceeded 5s timeout)... please remove leftover files in " <> T.pack recycleDir <> " manually"))
+                      (threadDelay 5000000 >> runLogger (logWarn $ "Killing cleanup thread (exceeded 5s timeout)... please remove leftover files in " <> T.pack (fromGHCupPath recycleDir) <> " manually"))

                case optCommand of
                  Nuke -> pure ()
@@ -239,20 +238,16 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                    | Just False <- optVerbose -> pure ()
                    | otherwise -> lookupEnv "GHCUP_SKIP_UPDATE_CHECK" >>= \case
                         Nothing -> void . flip runReaderT s' . runE @'[TagNotFound, NextVerNotFound, NoToolVersionSet] $ do
-                           newTools <- lift checkForUpdates 
+                           newTools <- lift checkForUpdates
                           forM_ newTools $ \newTool@(t, l) -> do
                             -- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/283
                             alreadyInstalling' <- alreadyInstalling optCommand newTool
                             when (not alreadyInstalling') $
                               case t of
-#ifdef DISABLE_UPGRADE
-                                 GHCup -> pure ()
-#else
                                 GHCup -> runLogger $
                                            logWarn ("New GHCup version available: "
                                              <> prettyVer l
                                              <> ". To upgrade, run 'ghcup upgrade'")
-#endif
                                 _ -> runLogger $
                                        logWarn ("New "
                                          <> T.pack (prettyShow t)
@@ -284,7 +279,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
              runAppState action' = do
                s' <- liftIO appState
                runReaderT action' s'
-                  
+

          -----------------
          -- Run command --
@@ -296,26 +291,24 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
              s' <- appState
              liftIO $ brickMain s' >> pure ExitSuccess
 #endif
-            Install installCommand   -> install installCommand settings appState runLogger
-            InstallCabalLegacy iopts -> install (Left (InstallCabal iopts)) settings appState runLogger
-            Set setCommand           -> set setCommand runAppState runLeanAppState runLogger
-            UnSet unsetCommand       -> unset unsetCommand runLeanAppState runLogger
-            List lo                  -> list lo no_color runAppState
-            Rm rmCommand             -> rm rmCommand runAppState runLogger
-            DInfo                    -> dinfo runAppState runLogger
-            Compile compileCommand   -> compile compileCommand settings dirs runAppState runLogger
-            Config configCommand     -> config configCommand settings keybindings runLogger
+            Install installCommand     -> install installCommand settings appState runLogger
+            InstallCabalLegacy iopts   -> install (Left (InstallCabal iopts)) settings appState runLogger
+            Set setCommand             -> set setCommand runAppState runLeanAppState runLogger
+            UnSet unsetCommand         -> unset unsetCommand runLeanAppState runLogger
+            List lo                    -> list lo no_color runAppState
+            Rm rmCommand               -> rm rmCommand runAppState runLogger
+            DInfo                      -> dinfo runAppState runLogger
+            Compile compileCommand     -> compile compileCommand settings dirs runAppState runLogger
+            Config configCommand       -> config configCommand settings keybindings runLogger
            Whereis whereisOptions
-                    whereisCommand   -> whereis whereisCommand whereisOptions runAppState leanAppstate runLogger
-#ifndef DISABLE_UPGRADE
-            Upgrade uOpts force'     -> upgrade uOpts force' dirs runAppState runLogger
-#endif
-            ToolRequirements topts   -> toolRequirements topts runAppState runLogger
-            ChangeLog changelogOpts  -> changelog changelogOpts runAppState runLogger
-            Nuke                     -> nuke appState runLogger
-            Prefetch pfCom           -> prefetch pfCom runAppState runLogger
-            GC gcOpts                -> gc gcOpts runAppState runLogger
-            Run runCommand           -> run runCommand appState leanAppstate runLogger
+                    whereisCommand     -> whereis whereisCommand whereisOptions runAppState leanAppstate runLogger
+            Upgrade uOpts force' fatal -> upgrade uOpts force' fatal dirs runAppState runLogger
+            ToolRequirements topts     -> toolRequirements topts runAppState runLogger
+            ChangeLog changelogOpts    -> changelog changelogOpts runAppState runLogger
+            Nuke                       -> nuke appState runLogger
+            Prefetch pfCom             -> prefetch pfCom runAppState runLogger
+            GC gcOpts                  -> gc gcOpts runAppState runLogger
+            Run runCommand             -> run runCommand appState leanAppstate runLogger

          case res of
            ExitSuccess        -> pure ()
@@ -346,16 +339,16 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
  alreadyInstalling (Install (Left (InstallHLS InstallOptions{..})))     (HLS, ver)   = cmp' HLS instVer ver
  alreadyInstalling (Install (Left (InstallStack InstallOptions{..})))   (Stack, ver) = cmp' Stack instVer ver
  alreadyInstalling (Compile (CompileGHC GHCCompileOptions{ ovewrwiteVer = Just over }))
-    (GHC, ver)   = cmp' GHC (Just $ ToolVersion (mkTVer over)) ver
-  alreadyInstalling (Compile (CompileGHC GHCCompileOptions{ targetGhc = Left tver }))
-    (GHC, ver)   = cmp' GHC (Just $ ToolVersion (mkTVer tver)) ver
-  alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ ovewrwiteVer = Just over }))
-    (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer over)) ver
-  alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = Left tver }))
-    (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer tver)) ver
-#ifndef DISABLE_UPGRADE
-  alreadyInstalling (Upgrade _ _) (GHCup, _) = pure True
-#endif
+    (GHC, ver)   = cmp' GHC (Just $ GHCVersion (mkTVer over)) ver
+  alreadyInstalling (Compile (CompileGHC GHCCompileOptions{ targetGhc = GHC.SourceDist tver }))
+    (GHC, ver)   = cmp' GHC (Just $ ToolVersion tver) ver
+  alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ ovewrwiteVer = Right over }))
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion over) ver
+  alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = HLS.SourceDist tver }))
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion tver) ver
+  alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = HLS.HackageDist tver }))
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion tver) ver
+  alreadyInstalling (Upgrade {}) (GHCup, _) = pure True
  alreadyInstalling _ _ = pure False

  cmp' :: ( HasLog env
--- a/cabal.ghc8107.project
+++ b/cabal.ghc8107.project
@@ -15,7 +15,7 @@ source-repository-package

 constraints: http-io-streams -brotli,
             any.Cabal ==3.6.2.0,
-             any.aeson >= 2.0.1.0
+             any.aeson >= 2.0.1.0,

 package libarchive
  flags: -system-libarchive
@@ -29,6 +29,9 @@ package cabal-plan
 package aeson
  flags: +ordered-keymap

+package streamly
+  flags: +use-unliftio
+
 allow-newer: base, ghc-prim, template-haskell, language-c

 with-compiler: ghc-8.10.7
--- a/cabal.ghc8107.project.freeze
+++ b/cabal.ghc8107.project.freeze
@@ -15,7 +15,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.aeson-pretty ==0.8.9,
             aeson-pretty +lib-only,
             any.alex ==3.2.7.1,
-             any.ansi-terminal ==0.11.1,
+             any.ansi-terminal ==0.11.3,
             ansi-terminal -example,
             any.ansi-wl-pprint ==0.6.9,
             ansi-wl-pprint -example,
@@ -33,7 +33,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.base-orphans ==0.8.6,
             any.base16-bytestring ==1.0.2.0,
             any.base64-bytestring ==1.2.1.0,
-             any.bifunctors ==5.5.11,
+             any.bifunctors ==5.5.12,
             bifunctors +semigroups +tagged,
             any.binary ==0.8.8.0,
             any.blaze-builder ==0.4.2.2,
@@ -80,9 +80,9 @@ constraints: any.Cabal ==3.6.2.0,
             dlist -werror,
             any.exceptions ==0.10.4,
             any.filepath ==1.4.2.1,
-             any.free ==5.1.7,
+             any.free ==5.1.8,
             any.fusion-plugin-types ==0.1.0,
-             any.generic-arbitrary ==0.2.0,
+             any.generic-arbitrary ==0.2.2,
             any.ghc ==8.10.7,
             any.ghc-boot ==8.10.7,
             any.ghc-boot-th ==8.10.7,
@@ -100,12 +100,12 @@ constraints: any.Cabal ==3.6.2.0,
             any.hpc ==0.6.1.0,
             any.hsc2hs ==0.68.8,
             hsc2hs -in-ghc-tree,
-             any.hspec ==2.9.4,
-             any.hspec-core ==2.9.4,
-             any.hspec-discover ==2.9.4,
+             any.hspec ==2.9.7,
+             any.hspec-core ==2.9.7,
+             any.hspec-discover ==2.9.7,
             any.hspec-expectations ==0.8.2,
             any.hspec-golden-aeson ==0.9.0.0,
-             any.http-io-streams ==0.1.6.0,
+             any.http-io-streams ==0.1.6.1,
             http-io-streams -brotli +fast-xor,
             any.indexed-profunctors ==0.1.1,
             any.indexed-traversable ==0.1.2,
@@ -115,7 +115,7 @@ constraints: any.Cabal ==3.6.2.0,
             integer-logarithms -check-bounds +integer-gmp,
             any.io-streams ==1.5.2.1,
             io-streams +network -nointeractivetests +zlib,
-             any.language-c ==0.9.0.1,
+             any.language-c ==0.9.1,
             language-c -allwarnings +iecfpextension +usebytestrings,
             any.libarchive ==3.0.3.2,
             libarchive -cross -low-memory +no-exe -system-libarchive,
@@ -123,22 +123,21 @@ constraints: any.Cabal ==3.6.2.0,
             libyaml-streamly -no-unicode -system-libyaml,
             any.lockfree-queue ==0.2.3.1,
             any.lzma-static ==5.2.5.4,
-             any.megaparsec ==9.2.0,
+             any.megaparsec ==9.2.1,
             megaparsec -dev,
             any.microlens ==0.4.12.0,
-             any.microlens-mtl ==0.2.0.1,
+             any.microlens-mtl ==0.2.0.2,
             any.microlens-th ==0.4.3.10,
-             any.monad-control ==1.0.3.1,
             any.mtl ==2.2.2,
             any.network ==3.1.2.7,
             network -devel,
             any.network-uri ==2.6.4.1,
             any.openssl-streams ==1.2.3.0,
-             any.optics ==0.4,
-             any.optics-core ==0.4,
+             any.optics ==0.4.2,
+             any.optics-core ==0.4.1,
             optics-core -explicit-generic-labels,
-             any.optics-extra ==0.4,
-             any.optics-th ==0.4,
+             any.optics-extra ==0.4.2.1,
+             any.optics-th ==0.4.1,
             any.optparse-applicative ==0.17.0.0,
             optparse-applicative +process,
             any.os-release ==1.0.2.1,
@@ -150,23 +149,23 @@ constraints: any.Cabal ==3.6.2.0,
             any.polyparse ==1.13,
             any.pretty ==1.1.3.6,
             any.pretty-terminal ==0.1.0.0,
-             any.primitive ==0.7.3.0,
+             any.primitive ==0.7.4.0,
             any.process ==1.6.13.2,
             any.profunctors ==5.6.2,
             any.quickcheck-arbitrary-adt ==0.3.1.0,
             any.quickcheck-io ==0.2.0,
-             any.random ==1.2.1,
+             any.random ==1.2.1.1,
             any.recursion-schemes ==5.2.2.2,
             recursion-schemes +template-haskell,
             any.regex-base ==0.94.0.2,
             any.regex-posix ==0.96.0.1,
             regex-posix -_regex-posix-clib,
-             any.resourcet ==1.2.4.3,
+             any.resourcet ==1.2.5,
             any.retry ==0.8.1.2,
             retry -lib-werror,
             any.rts ==1.0.1,
             any.safe ==0.3.19,
-             any.safe-exceptions ==0.1.7.2,
+             any.safe-exceptions ==0.1.7.3,
             any.scientific ==0.3.7.0,
             scientific -bytestring-builder -integer-simple,
             any.semialign ==1.2.0.1,
@@ -179,7 +178,7 @@ constraints: any.Cabal ==3.6.2.0,
             splitmix -optimised-mixer,
             any.stm ==2.5.0.1,
             any.streamly ==0.8.2,
-             streamly -debug -dev -fusion-plugin -has-llvm -inspection -limit-build-mem -no-fusion +opt -streamk -streamly-core -use-c-malloc -use-unliftio,
+             streamly -debug -dev -fusion-plugin -has-llvm -inspection -limit-build-mem -no-fusion +opt -streamk -streamly-core -use-c-malloc +use-unliftio,
             any.strict ==0.4.0.1,
             strict +assoc,
             any.strict-base ==0.4.0.0,
@@ -213,11 +212,11 @@ constraints: any.Cabal ==3.6.2.0,
             any.unicode-data ==0.3.0,
             unicode-data -ucd2haskell,
             any.unix ==2.7.2.2,
-             any.unix-bytestring ==0.3.7.6,
-             any.unix-compat ==0.5.4,
+             any.unix-bytestring ==0.3.7.7,
+             any.unix-compat ==0.6,
             unix-compat -old-time,
             any.unliftio-core ==0.2.0.1,
-             any.unordered-containers ==0.2.17.0,
+             any.unordered-containers ==0.2.19.1,
             unordered-containers -debug,
             any.uri-bytestring ==0.3.3.1,
             uri-bytestring -lib-werror,
@@ -233,7 +232,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.xor ==0.0.1.1,
             any.yaml-streamly ==0.12.1,
             yaml-streamly +no-examples +no-exe,
-             any.zlib ==0.6.2.3,
+             any.zlib ==0.6.3.0,
             zlib -bundled-c-zlib -non-blocking-ffi -pkg-config,
             any.zlib-bindings ==0.1.1.5
-index-state: hackage.haskell.org 2022-03-15T16:43:02Z
+index-state: hackage.haskell.org 2022-06-04T19:47:01Z
--- a/cabal.ghc902.project
+++ b/cabal.ghc902.project
@@ -15,7 +15,7 @@ source-repository-package

 constraints: http-io-streams -brotli,
             any.Cabal ==3.6.2.0,
-             any.aeson >= 2.0.1.0
+             any.aeson >= 2.0.1.0,

 package libarchive
  flags: -system-libarchive
@@ -29,6 +29,9 @@ package cabal-plan
 package aeson
  flags: +ordered-keymap

+package streamly
+  flags: +use-unliftio
+
 allow-newer: base, ghc-prim, template-haskell, language-c

 with-compiler: ghc-9.0.2
--- a/cabal.ghc902.project.freeze
+++ b/cabal.ghc902.project.freeze
@@ -15,7 +15,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.aeson-pretty ==0.8.9,
             aeson-pretty +lib-only,
             any.alex ==3.2.7.1,
-             any.ansi-terminal ==0.11.1,
+             any.ansi-terminal ==0.11.3,
             ansi-terminal -example,
             any.ansi-wl-pprint ==0.6.9,
             ansi-wl-pprint -example,
@@ -33,7 +33,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.base-orphans ==0.8.6,
             any.base16-bytestring ==1.0.2.0,
             any.base64-bytestring ==1.2.1.0,
-             any.bifunctors ==5.5.11,
+             any.bifunctors ==5.5.12,
             bifunctors +semigroups +tagged,
             any.binary ==0.8.8.0,
             any.blaze-builder ==0.4.2.2,
@@ -80,9 +80,9 @@ constraints: any.Cabal ==3.6.2.0,
             dlist -werror,
             any.exceptions ==0.10.4,
             any.filepath ==1.4.2.1,
-             any.free ==5.1.7,
+             any.free ==5.1.8,
             any.fusion-plugin-types ==0.1.0,
-             any.generic-arbitrary ==0.2.0,
+             any.generic-arbitrary ==0.2.2,
             any.ghc ==9.0.2,
             any.ghc-bignum ==1.1,
             any.ghc-boot ==9.0.2,
@@ -101,12 +101,12 @@ constraints: any.Cabal ==3.6.2.0,
             any.hpc ==0.6.1.0,
             any.hsc2hs ==0.68.8,
             hsc2hs -in-ghc-tree,
-             any.hspec ==2.9.4,
-             any.hspec-core ==2.9.4,
-             any.hspec-discover ==2.9.4,
+             any.hspec ==2.9.7,
+             any.hspec-core ==2.9.7,
+             any.hspec-discover ==2.9.7,
             any.hspec-expectations ==0.8.2,
             any.hspec-golden-aeson ==0.9.0.0,
-             any.http-io-streams ==0.1.6.0,
+             any.http-io-streams ==0.1.6.1,
             http-io-streams -brotli +fast-xor,
             any.indexed-profunctors ==0.1.1,
             any.indexed-traversable ==0.1.2,
@@ -115,7 +115,7 @@ constraints: any.Cabal ==3.6.2.0,
             integer-logarithms -check-bounds +integer-gmp,
             any.io-streams ==1.5.2.1,
             io-streams +network -nointeractivetests +zlib,
-             any.language-c ==0.9.0.1,
+             any.language-c ==0.9.1,
             language-c -allwarnings +iecfpextension +usebytestrings,
             any.libarchive ==3.0.3.2,
             libarchive -cross -low-memory +no-exe -system-libarchive,
@@ -123,22 +123,21 @@ constraints: any.Cabal ==3.6.2.0,
             libyaml-streamly -no-unicode -system-libyaml,
             any.lockfree-queue ==0.2.3.1,
             any.lzma-static ==5.2.5.4,
-             any.megaparsec ==9.2.0,
+             any.megaparsec ==9.2.1,
             megaparsec -dev,
             any.microlens ==0.4.12.0,
-             any.microlens-mtl ==0.2.0.1,
+             any.microlens-mtl ==0.2.0.2,
             any.microlens-th ==0.4.3.10,
-             any.monad-control ==1.0.3.1,
             any.mtl ==2.2.2,
             any.network ==3.1.2.7,
             network -devel,
             any.network-uri ==2.6.4.1,
             any.openssl-streams ==1.2.3.0,
-             any.optics ==0.4,
-             any.optics-core ==0.4,
+             any.optics ==0.4.2,
+             any.optics-core ==0.4.1,
             optics-core -explicit-generic-labels,
-             any.optics-extra ==0.4,
-             any.optics-th ==0.4,
+             any.optics-extra ==0.4.2.1,
+             any.optics-th ==0.4.1,
             any.optparse-applicative ==0.17.0.0,
             optparse-applicative +process,
             any.os-release ==1.0.2.1,
@@ -150,23 +149,23 @@ constraints: any.Cabal ==3.6.2.0,
             any.polyparse ==1.13,
             any.pretty ==1.1.3.6,
             any.pretty-terminal ==0.1.0.0,
-             any.primitive ==0.7.3.0,
+             any.primitive ==0.7.4.0,
             any.process ==1.6.13.2,
             any.profunctors ==5.6.2,
             any.quickcheck-arbitrary-adt ==0.3.1.0,
             any.quickcheck-io ==0.2.0,
-             any.random ==1.2.1,
+             any.random ==1.2.1.1,
             any.recursion-schemes ==5.2.2.2,
             recursion-schemes +template-haskell,
             any.regex-base ==0.94.0.2,
             any.regex-posix ==0.96.0.1,
             regex-posix -_regex-posix-clib,
-             any.resourcet ==1.2.4.3,
+             any.resourcet ==1.2.5,
             any.retry ==0.8.1.2,
             retry -lib-werror,
             any.rts ==1.0.2,
             any.safe ==0.3.19,
-             any.safe-exceptions ==0.1.7.2,
+             any.safe-exceptions ==0.1.7.3,
             any.scientific ==0.3.7.0,
             scientific -bytestring-builder -integer-simple,
             any.semialign ==1.2.0.1,
@@ -179,7 +178,7 @@ constraints: any.Cabal ==3.6.2.0,
             splitmix -optimised-mixer,
             any.stm ==2.5.0.0,
             any.streamly ==0.8.2,
-             streamly -debug -dev -fusion-plugin -has-llvm -inspection -limit-build-mem -no-fusion +opt -streamk -streamly-core -use-c-malloc -use-unliftio,
+             streamly -debug -dev -fusion-plugin -has-llvm -inspection -limit-build-mem -no-fusion +opt -streamk -streamly-core -use-c-malloc +use-unliftio,
             any.strict ==0.4.0.1,
             strict +assoc,
             any.strict-base ==0.4.0.0,
@@ -213,11 +212,11 @@ constraints: any.Cabal ==3.6.2.0,
             any.unicode-data ==0.3.0,
             unicode-data -ucd2haskell,
             any.unix ==2.7.2.2,
-             any.unix-bytestring ==0.3.7.6,
-             any.unix-compat ==0.5.4,
+             any.unix-bytestring ==0.3.7.7,
+             any.unix-compat ==0.6,
             unix-compat -old-time,
             any.unliftio-core ==0.2.0.1,
-             any.unordered-containers ==0.2.17.0,
+             any.unordered-containers ==0.2.19.1,
             unordered-containers -debug,
             any.uri-bytestring ==0.3.3.1,
             uri-bytestring -lib-werror,
@@ -233,7 +232,7 @@ constraints: any.Cabal ==3.6.2.0,
             any.xor ==0.0.1.1,
             any.yaml-streamly ==0.12.1,
             yaml-streamly +no-examples +no-exe,
-             any.zlib ==0.6.2.3,
+             any.zlib ==0.6.3.0,
             zlib -bundled-c-zlib -non-blocking-ffi -pkg-config,
             any.zlib-bindings ==0.1.1.5
-index-state: hackage.haskell.org 2022-03-15T16:43:02Z
+index-state: hackage.haskell.org 2022-06-04T19:47:01Z
--- a/cabal.ghc923.project
+++ b/cabal.ghc923.project
@@ -0,0 +1,37 @@
+packages: ./ghcup.cabal
+
+optional-packages: ./vendored/*/*.cabal
+
+optimization: 2
+
+package ghcup
+    tests: True
+    flags: +tui
+
+source-repository-package
+  type: git
+  location: https://github.com/bgamari/terminal-size.git
+  tag: 34ea816bd63f75f800eedac12c6908c6f3736036
+
+constraints: http-io-streams -brotli,
+             any.Cabal ==3.6.2.0,
+             any.aeson >= 2.0.1.0,
+
+package libarchive
+  flags: -system-libarchive
+
+package aeson-pretty
+  flags: +lib-only
+
+package cabal-plan
+  flags: -exe
+
+package aeson
+  flags: +ordered-keymap
+
+package streamly
+  flags: +use-unliftio
+
+allow-newer: base, ghc-prim, template-haskell, language-c
+
+with-compiler: ghc-9.2.3
--- a/cabal.ghc923.project.freeze
+++ b/cabal.ghc923.project.freeze
@@ -0,0 +1,233 @@
+active-repositories: hackage.haskell.org:merge
+constraints: any.Cabal ==3.6.2.0,
+             Cabal -bundled-binary-generic,
+             any.HUnit ==1.6.2.0,
+             any.HsOpenSSL ==0.11.7.2,
+             HsOpenSSL -fast-bignum -homebrew-openssl -macports-openssl -use-pkg-config,
+             any.OneTuple ==0.3.1,
+             any.QuickCheck ==2.14.2,
+             QuickCheck -old-random +templatehaskell,
+             any.StateVar ==1.2.2,
+             any.abstract-deque ==0.3,
+             abstract-deque -usecas,
+             any.aeson ==2.0.3.0,
+             aeson -cffi +ordered-keymap,
+             any.aeson-pretty ==0.8.9,
+             aeson-pretty +lib-only,
+             any.alex ==3.2.7.1,
+             any.ansi-terminal ==0.11.3,
+             ansi-terminal -example,
+             any.ansi-wl-pprint ==0.6.9,
+             ansi-wl-pprint -example,
+             any.array ==0.5.4.0,
+             any.assoc ==1.0.2,
+             any.async ==2.2.4,
+             async -bench,
+             any.atomic-primops ==0.8.4,
+             atomic-primops -debug,
+             any.attoparsec ==0.14.4,
+             attoparsec -developer,
+             any.base ==4.16.2.0,
+             any.base-compat ==0.12.1,
+             any.base-compat-batteries ==0.12.1,
+             any.base-orphans ==0.8.6,
+             any.base16-bytestring ==1.0.2.0,
+             any.base64-bytestring ==1.2.1.0,
+             any.bifunctors ==5.5.12,
+             bifunctors +semigroups +tagged,
+             any.binary ==0.8.9.0,
+             any.blaze-builder ==0.4.2.2,
+             any.brick ==0.64.2,
+             brick -demos,
+             any.bytestring ==0.11.3.1,
+             any.bz2 ==1.0.1.0,
+             bz2 -cross +with-bzlib,
+             any.c2hs ==0.28.8,
+             c2hs +base3 -regression,
+             any.cabal-plan ==0.7.2.1,
+             cabal-plan -_ -exe -license-report,
+             any.call-stack ==0.4.0,
+             any.case-insensitive ==1.2.1.0,
+             any.casing ==0.1.4.1,
+             any.chs-cabal ==0.1.1.1,
+             any.chs-deps ==0.1.0.0,
+             chs-deps -cross,
+             any.clock ==0.8.3,
+             clock -llvm,
+             any.colour ==2.3.6,
+             any.comonad ==5.0.8,
+             comonad +containers +distributive +indexed-traversable,
+             any.composition-prelude ==3.0.0.2,
+             composition-prelude -development,
+             any.config-ini ==0.2.4.0,
+             config-ini -enable-doctests,
+             any.containers ==0.6.5.1,
+             any.contravariant ==1.5.5,
+             contravariant +semigroups +statevar +tagged,
+             any.cpphs ==1.20.9.1,
+             cpphs -old-locale,
+             any.cryptohash-sha1 ==0.11.101.0,
+             any.cryptohash-sha256 ==0.11.102.1,
+             cryptohash-sha256 -exe +use-cbits,
+             any.data-clist ==0.2,
+             any.data-fix ==0.3.2,
+             any.deepseq ==1.4.6.1,
+             any.directory ==1.3.7.0,
+             any.disk-free-space ==0.1.0.1,
+             any.distributive ==0.6.2.1,
+             distributive +semigroups +tagged,
+             any.dlist ==1.0,
+             dlist -werror,
+             any.exceptions ==0.10.4,
+             any.filepath ==1.4.2.2,
+             any.free ==5.1.8,
+             any.fusion-plugin-types ==0.1.0,
+             any.generic-arbitrary ==0.2.2,
+             any.ghc-bignum ==1.2,
+             any.ghc-boot-th ==9.2.3,
+             any.ghc-byteorder ==4.11.0.0.10,
+             any.ghc-prim ==0.8.0,
+             any.happy ==1.20.0,
+             any.hashable ==1.4.0.2,
+             hashable +containers +integer-gmp -random-initial-seed,
+             any.haskus-utils-data ==1.4,
+             any.haskus-utils-types ==1.5.1,
+             any.haskus-utils-variant ==3.2.1,
+             any.heaps ==0.4,
+             any.hsc2hs ==0.68.8,
+             hsc2hs -in-ghc-tree,
+             any.hspec ==2.9.2,
+             any.hspec-core ==2.9.2,
+             any.hspec-discover ==2.9.2,
+             any.hspec-expectations ==0.8.2,
+             any.hspec-golden-aeson ==0.9.0.0,
+             any.http-io-streams ==0.1.6.1,
+             http-io-streams -brotli +fast-xor,
+             any.indexed-profunctors ==0.1.1,
+             any.indexed-traversable ==0.1.2,
+             any.indexed-traversable-instances ==0.1.1,
+             any.integer-logarithms ==1.0.3.1,
+             integer-logarithms -check-bounds +integer-gmp,
+             any.io-streams ==1.5.2.1,
+             io-streams +network -nointeractivetests +zlib,
+             any.language-c ==0.9.1,
+             language-c -allwarnings +iecfpextension +usebytestrings,
+             any.libarchive ==3.0.3.2,
+             libarchive -cross -low-memory +no-exe -system-libarchive,
+             any.libyaml-streamly ==0.2.1,
+             libyaml-streamly -no-unicode -system-libyaml,
+             any.lockfree-queue ==0.2.3.1,
+             any.lzma-static ==5.2.5.4,
+             any.megaparsec ==9.2.1,
+             megaparsec -dev,
+             any.microlens ==0.4.12.0,
+             any.microlens-mtl ==0.2.0.2,
+             any.microlens-th ==0.4.3.10,
+             any.mtl ==2.2.2,
+             any.network ==3.1.2.7,
+             network -devel,
+             any.network-uri ==2.6.4.1,
+             any.openssl-streams ==1.2.3.0,
+             any.optics ==0.4.2,
+             any.optics-core ==0.4.1,
+             optics-core -explicit-generic-labels,
+             any.optics-extra ==0.4.2.1,
+             any.optics-th ==0.4.1,
+             any.optparse-applicative ==0.17.0.0,
+             optparse-applicative +process,
+             any.os-release ==1.0.2.1,
+             os-release -devel,
+             any.parallel ==3.2.2.0,
+             any.parsec ==3.1.15.0,
+             any.parser-combinators ==1.3.0,
+             parser-combinators -dev,
+             any.polyparse ==1.13,
+             any.pretty ==1.1.3.6,
+             any.pretty-terminal ==0.1.0.0,
+             any.primitive ==0.7.4.0,
+             any.process ==1.6.14.0,
+             any.profunctors ==5.6.2,
+             any.quickcheck-arbitrary-adt ==0.3.1.0,
+             any.quickcheck-io ==0.2.0,
+             any.random ==1.2.1.1,
+             any.recursion-schemes ==5.2.2.2,
+             recursion-schemes +template-haskell,
+             any.regex-base ==0.94.0.2,
+             any.regex-posix ==0.96.0.1,
+             regex-posix -_regex-posix-clib,
+             any.resourcet ==1.2.5,
+             any.retry ==0.8.1.2,
+             retry -lib-werror,
+             any.rts ==1.0.2,
+             any.safe ==0.3.19,
+             any.safe-exceptions ==0.1.7.3,
+             any.scientific ==0.3.7.0,
+             scientific -bytestring-builder -integer-simple,
+             any.semialign ==1.2.0.1,
+             semialign +semigroupoids,
+             any.semigroupoids ==5.3.7,
+             semigroupoids +comonad +containers +contravariant +distributive +tagged +unordered-containers,
+             any.setenv ==0.1.1.3,
+             any.split ==0.2.3.4,
+             any.splitmix ==0.1.0.4,
+             splitmix -optimised-mixer,
+             any.stm ==2.5.0.2,
+             any.streamly ==0.8.2,
+             streamly -debug -dev -fusion-plugin -has-llvm -inspection -limit-build-mem -no-fusion +opt -streamk -streamly-core -use-c-malloc +use-unliftio,
+             any.strict ==0.4.0.1,
+             strict +assoc,
+             any.strict-base ==0.4.0.0,
+             any.tagged ==0.8.6.1,
+             tagged +deepseq +transformers,
+             any.tagsoup ==0.14.8,
+             any.template-haskell ==2.18.0.0,
+             any.temporary ==1.3,
+             any.terminal-progress-bar ==0.4.1,
+             any.terminal-size ==0.3.2.1,
+             any.terminfo ==0.4.1.5,
+             any.text ==1.2.5.0,
+             any.text-short ==0.1.5,
+             text-short -asserts,
+             any.text-zipper ==0.11,
+             any.tf-random ==0.5,
+             any.th-abstraction ==0.4.3.0,
+             any.th-compat ==0.1.3,
+             any.th-lift ==0.8.2,
+             any.th-lift-instances ==0.1.19,
+             any.these ==1.1.1.1,
+             these +assoc,
+             any.time ==1.9.3,
+             any.time-compat ==1.9.6.1,
+             time-compat -old-locale,
+             any.transformers ==0.5.6.2,
+             any.transformers-base ==0.4.6,
+             transformers-base +orphaninstances,
+             any.transformers-compat ==0.7.1,
+             transformers-compat -five +five-three -four +generic-deriving +mtl -three -two,
+             any.unicode-data ==0.3.0,
+             unicode-data -ucd2haskell,
+             any.unix ==2.7.2.2,
+             any.unix-bytestring ==0.3.7.7,
+             any.unix-compat ==0.6,
+             unix-compat -old-time,
+             any.unliftio-core ==0.2.0.1,
+             any.unordered-containers ==0.2.19.1,
+             unordered-containers -debug,
+             any.uri-bytestring ==0.3.3.1,
+             uri-bytestring -lib-werror,
+             any.utf8-string ==1.0.2,
+             any.uuid-types ==1.0.5,
+             any.vector ==0.12.3.1,
+             vector +boundschecks -internalchecks -unsafechecks -wall,
+             any.versions ==5.0.3,
+             any.vty ==5.33,
+             any.witherable ==0.4.2,
+             any.word-wrap ==0.5,
+             any.word8 ==0.1.3,
+             any.xor ==0.0.1.1,
+             any.yaml-streamly ==0.12.1,
+             yaml-streamly +no-examples +no-exe,
+             any.zlib ==0.6.3.0,
+             zlib -bundled-c-zlib -non-blocking-ffi -pkg-config,
+             any.zlib-bindings ==0.1.1.5
+index-state: hackage.haskell.org 2022-06-04T19:47:01Z
--- a/cabal.project
+++ b/cabal.project
@@ -5,7 +5,6 @@ optional-packages: ./vendored/*/*.cabal
 optimization: 2

 package ghcup
-    tests: True
    flags: +tui

 source-repository-package
@@ -16,8 +15,6 @@ source-repository-package
 constraints: http-io-streams -brotli,
             any.Cabal ==3.6.2.0,
             any.aeson >= 2.0.1.0,
-             -- https://github.com/typeable/generic-arbitrary/issues/14
-             any.generic-arbitrary < 0.2.1

 package libarchive
  flags: -system-libarchive
@@ -31,4 +28,7 @@ package cabal-plan
 package aeson
  flags: +ordered-keymap

+package streamly
+  flags: +use-unliftio
+
 allow-newer: base, ghc-prim, template-haskell, language-c
--- a/cbits/dirutils.c
+++ b/cbits/dirutils.c
@@ -0,0 +1,7 @@
+#include "dirutils.h"
+
+unsigned int
+    __posixdir_d_type(struct dirent* d)
+    {
+      return(d -> d_type);
+    }
--- a/cbits/dirutils.h
+++ b/cbits/dirutils.h
@@ -0,0 +1,15 @@
+#ifndef POSIXPATHS_CBITS_DIRUTILS_H
+#define POSIXPATHS_CBITS_DIRUTILS_H
+
+#include <stdlib.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+
+extern unsigned int
+    __posixdir_d_type(struct dirent* d)
+    ;
+
+#endif
--- a/data/metadata
+++ b/data/metadata
--- a/docs/about.md
+++ b/docs/about.md
@@ -74,12 +74,15 @@ cabal-install/HLS/stack are installed in `~/.ghcup/bin/<tool>-<ver>` and have un

 ## Known users

-* Github actions:
-	- [actions/virtual-environments](https://github.com/actions/virtual-environments)
-	- [haskell/actions/setup](https://github.com/haskell/actions/tree/main/setup)
+* CI:
+	- [Github actions/virtual-environments](https://github.com/actions/virtual-environments)
+	- [Github haskell/actions/setup](https://github.com/haskell/actions/tree/main/setup)
+	- [haskell-ci](https://github.com/haskell-CI/haskell-ci)
 * mirrors:
 	- [sjtug](https://mirror.sjtu.edu.cn/docs/ghcup)
 * tools:
+	- [vscode-haskell](https://github.com/haskell/vscode-haskell)
+	- [nvim-lsp-installer](https://github.com/williamboman/nvim-lsp-installer)
 	- [vabal](https://github.com/Franciman/vabal)

 ## Known problems
--- a/docs/guide.md
+++ b/docs/guide.md
@@ -4,7 +4,7 @@ This is a more in-depth guide specific to GHCup. `ghcup --help` is your friend.

 ## Basic usage

-For the simple interactive TUI (not available on windows), run:
+For the simple, interactive, text-based user interface (TUI) (not available on windows), run:

 ```sh
 ghcup tui
@@ -57,6 +57,13 @@ as e.g. `/etc/bash_completion.d/ghcup` (depending on distro)
 and make sure your bashrc sources the startup script
 (`/usr/share/bash-completion/bash_completion` on some distros).

+## Portability
+
+`ghcup` is very portable. There are a few exceptions though:
+
+1. `ghcup tui` is only available on non-windows platforms
+2. legacy subcommands `ghcup install` (without a tool identifier) and `ghcup install-cabal` may be removed in the future
+
 # Configuration

 A configuration file can be put in `~/.ghcup/config.yaml`. The default config file
@@ -69,7 +76,6 @@ Partial configuration is fine. Command line options always override the config f
 This is the complete list of env variables that change GHCup behavior:

 * `GHCUP_USE_XDG_DIRS`: see [XDG support](#xdg-support) above
-* `TMPDIR`: where ghcup does the work (unpacking, building, ...)
 * `GHCUP_INSTALL_BASE_PREFIX`: the base of ghcup (default: `$HOME`)
 * `GHCUP_CURL_OPTS`: additional options that can be passed to curl
 * `GHCUP_WGET_OPTS`: additional options that can be passed to wget
@@ -180,6 +186,51 @@ url-source:

 # More on installation

+## Customisation of the installation scripts
+
+The scripts offered to install GHCup are available here:
+
+* [bootstrap-haskell](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell#L7)
+  for Unix-like operating systems
+* [bootstrap-haskell.ps1](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell.ps1#L17)
+  for Windows (PowerShell). This will, in turn, run the final bootstrap script
+  (by default, that for the Unix-like operating systems).
+
+The effect of the scripts can be customised by setting one or more
+`BOOTSTRAP_HASKELL_*` environment variables (as set out in the first script)
+and, in the case of Windows, by specifying parameters (as set out in the
+PowerShell script).
+
+For example, you can toggle:
+
+* non-interactive installation
+* a more verbose installation
+* whether to install only GHCup (and, on Windows, MSYS2)
+* not to trigger the upgrade of GHCup
+* whether to install the latest version of HLS
+* whether to install the latest version of Stack
+* whether to respect the XDG Base Directory Specification
+* whether to adjust (prepend) the PATH in `bashrc`
+* on Windows, whether to adjust MINGW paths in `cabal.config`
+
+You can also specify:
+
+* the GHC version to install
+* the Cabal version to install
+* which downloader to use (the default is `curl`)
+* the base URL for the download of the GHCup binary distribution
+
+On Windows, you can also use the parameters to:
+
+* toggle whether to overwrite a previous installation
+* specify the GHCup installation root directory
+* specify the Cabal root directory
+* specify the directory of an existing installation of MSYS2 (for example,
+  the one supplied by Stack)
+* specify the URL of the final bootstrap script
+* toggle whether to run the final bootstrap script via `bash` (instead of in a
+  new MSYS2 shell)
+
 ## Installing custom bindists

 There are a couple of good use cases to install custom bindists:
@@ -187,7 +238,8 @@ There are a couple of good use cases to install custom bindists:
 1. manually built bindists (e.g. with patches)
    - example: `ghcup install ghc -u 'file:///home/mearwald/tmp/ghc-eff-patches/ghc-8.10.2-x86_64-deb10-linux.tar.xz' 8.10.2-eff`
 2. GHC head CI bindists
-    - example: `ghcup install ghc -u 'https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27' head`
+    - example specifying a branch (`master`): `ghcup install ghc -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head`
+    - example specifying a job id (`1129565`): `ghcup install ghc -u ' https://gitlab.haskell.org/api/v4/projects/1/jobs/1129565/artifacts/ghc-x86_64-linux-alpine3_12-validate+fully_static.tar.xz' mr7847`
 3. DWARF bindists
    - example: `ghcup install ghc -u 'https://downloads.haskell.org/~ghc/8.10.2/ghc-8.10.2-x86_64-deb10-linux-dwarf.tar.xz' 8.10.2-dwarf`

@@ -196,7 +248,9 @@ and produce the binaries `ghc-8.10.2-eff` and `ghc-head` respectively.
 GHCup always needs to know which version the bindist corresponds to (this is not automatically
 detected).

-## Compiling GHC from source
+## Compiling from source
+
+### GHC

 Compiling from source is supported for both source tarballs and arbitrary git refs. See `ghcup compile ghc --help`
 for a list of all available options.
@@ -208,6 +262,64 @@ Common `build.mk` options are explained [here](https://gitlab.haskell.org/ghc/gh

 Make sure your system meets all the [prerequisites](https://gitlab.haskell.org/ghc/ghc/-/wikis/building/preparation).

+### HLS
+
+There are 3 main ways to compile HLS from source.
+
+1. from hackage (should have up to date version bounds)
+    - `ghcup compile hls --version 1.7.0.0 --ghc 9.2.3`
+2. from git (allows to build latest sources and PRs)
+    - `ghcup compile hls --git-ref master --ghc 9.2.3`
+    - `ghcup compile hls --git-ref a32db0b --ghc 9.2.3`
+    - `ghcup compile hls --git-ref 1.7.0.0 --ghc 9.2.3`
+3. from source distribution that's packaged during release from the corresponding git sources
+    - `ghcup compile hls --source-dist 1.7.0.0 --ghc 9.2.3`
+
+All these use `cabal v2-install` under the hood, so all build components are cached.
+You can pass arbitrary arguments to cabal, e.g. set the index state like so:
+
+```sh
+ghcup compile hls --git-ref master --ghc 9.2.3 -- --index-state=2022-06-12T00:00:00Z --allow-newer
+```
+
+You can pass `--ghc <ver>` multiple times to install for many GHCs at once.
+
+When building from git sources, ghcup will auto-detect the HLS version that the git commit corresponds to
+from the `haskell-language-server.cabal` file. This version might not have been updated since the last release.
+If you want to avoid overwriting the existing installed HLS version, you can instruct ghcup to use `git describe`
+to set the HLS version instead:
+
+```sh
+ghcup compile hls --git-ref master --ghc 9.2.3 --git-describe-version
+```
+
+You can also set the version explicitly:
+
+```sh
+ghcup compile hls --git-ref master --ghc 9.2.3 --overwrite-version 1.7.0.0-p1
+```
+
+To instruct cabal to run `cabal update` before building, run `ghcup compile hls --version 1.7.0.0 --ghc 9.2.3 --cabal-update`
+
+As always, check `ghcup compile hls --help`.
+
+#### Updating HLS for a new GHC version
+
+First try to build from hackage with some tricks:
+
+```sh
+ghcup compile hls --version 1.7.0.0 --ghc 9.2.4 --cabal-update -- --allow-newer --index-state=2022-06-12T00:00:00Z
+```
+
+This augments the currently installed 1.7.0.0 official bindists in ghcup with new GHC versions support.
+
+If that fails (since `--allow-newer` is quite brutal), you can install from HLS master branch (which may contain new fixes) like so:
+```
+ghcup compile hls --git-ref master --git-describe-version --ghc 8.10.7 --ghc 9.2.4 --cabal-update
+```
+
+This however will create a new HLS version in ghcup, e.g. `1.7.0.0-105-gdc682ba1`, for both 8.10.7 and 9.2.4. If you want to switch back to the official bindists, run `ghcup set hls 1.7.0.0`.
+
 ### Cross support

 ghcup can compile and install a cross GHC for any target. However, this
@@ -221,6 +333,8 @@ See `ghcup compile ghc --help` for further information.

 ## Isolated installs

+**Before using isolated installs, make sure to have at least GHCup version 0.1.17.8!**
+
 Ghcup also enables you to install a tool (GHC, Cabal, HLS, Stack) at an isolated location of your choosing.
 These installs, as the name suggests, are separate from your main installs and DO NOT conflict with them.

@@ -233,24 +347,26 @@ You need to use the `--isolate` or `-i` flag followed by the directory path.

 Examples:

-1. install an isolated GHC version at location /home/user/isolated_dir/ghc/  
+1. install an isolated GHC version at location /home/user/isolated_dir/ghc/
    - `ghcup install ghc 8.10.5 --isolate /home/user/isolated_dir/ghc`

-2. isolated install Cabal at a location you desire  
+2. isolated install Cabal at a location you desire
    - `ghcup install cabal --isolate /home/username/my_isolated_dir/`

-3. do an isolated install with a custom bindist  
-    - `ghcup install ghc --isolate /home/username/my_isolated_dir/ -u 'https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27' head`
+3. do an isolated install with a custom bindist
+    - `ghcup install ghc --isolate /home/username/my_isolated_dir/ -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head`

-4. isolated install HLS  
+4. isolated install HLS
    - `ghcup install hls --isolate /home/username/dir/hls/`

-5. you can even compile ghc to an isolated location.  
-    - `ghcup compile ghc -j 4 -v 9.0.1 -b 8.10.5 -i /home/username/my/dir/ghc` 
+5. you can even compile ghc to an isolated location.
+    - `ghcup compile ghc -j 4 -v 9.0.1 -b 8.10.5 -i /home/username/my/dir/ghc`

 ## Continuous integration

-On windows, ghcup can be installed automatically on a CI runner non-interactively like so:
+On Windows, GHCup can be installed automatically on a CI runner
+non-interactively, as below. The paramaters to the PowerShell script are
+specified positionally, after `-ArgumentList`:

 ```ps
 Set-ExecutionPolicy Bypass -Scope Process -Force;[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072;Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Invoke-WebRequest https://www.haskell.org/ghcup/sh/bootstrap-haskell.ps1 -UseBasicParsing))) -ArgumentList $false,$true,$true,$false,$false,$false,$false,"C:\"
@@ -262,12 +378,10 @@ On linux/darwin/freebsd, run the following on your runner:
 curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | BOOTSTRAP_HASKELL_NONINTERACTIVE=1 BOOTSTRAP_HASKELL_MINIMAL=1 sh
 ```

-This will just install `ghcup` and on windows additionally `msys2`.
+This will just install `ghcup` and on Windows additionally MSYS2.

-For the full list of env variables and parameters to tweak the script behavior, see:
-
-* [bootstrap-haskell for linux/darwin/freebsd](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell#L7)
-* [bootstrap-haskell.ps1 for windows](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell.ps1#L17)
+See the installation scripts referred to above for the full list of environment
+variables and, in the case of Windows, parameters to tweak the script behavior.

 ### github workflows

@@ -279,10 +393,11 @@ GHCup itself is also pre-installed on all platforms, but may use non-standard in
 GHCup supports verifying the GPG signature of the metadata file. The metadata file then contains SHA256 hashes of all downloads, so
 this is cryptographically secure.

-First, obtain the gpg key:
+First, obtain the gpg keys:

 ```sh
-gpg --batch --keyserver keys.openpgp.org --recv-keys 7784930957807690A66EBDBE3786C5262ECB4A3F
+gpg --batch --keyserver keys.openpgp.org     --recv-keys 7784930957807690A66EBDBE3786C5262ECB4A3F
+gpg --batch --keyserver keyserver.ubuntu.com --recv-keys FE5AB6C91FEA597C3B31180B73EDE9E8CFBAEF01
 ```

 Then verify the gpg key in one of these ways:
@@ -301,7 +416,7 @@ gpg-setting: GPGLax # GPGStrict | GPGLax | GPGNone

 In `GPGStrict` mode, ghcup will fail if verification fails. In `GPGLax` mode it will just print a warning.
 You can also pass the mode via `ghcup --gpg <strict|lax|none>`.
-   
+
 # Tips and tricks

 ## ghcup run
@@ -315,3 +430,34 @@ ghcup run --ghc 8.10.7 --cabal latest --hls latest --stack latest --install -- c
 ```

 This will execute vscode with GHC set to 8.10.7 and all other tools to their latest version.
+
+# Troubleshooting
+
+## Script immediately exits on windows
+
+There are two possible reasons:
+
+1. your company blocks the script (some have a whitelist)... ask your administrator
+2. your Antivirus or Windows Defender interfere with the installation. Disable them temporarily.
+
+## C compiler cannot create executables
+
+### Darwin
+
+You need to update your XCode command line tools, e.g. [like this](https://stackoverflow.com/questions/34617452/how-to-update-xcode-from-command-line).
+
+## Certificate authority errors (curl)
+
+If your certificates are outdated or improperly configured, curl may be unable
+to download ghcup.
+
+There are two known workarounds:
+
+1. Tell curl to ignore certificate errors (dangerous): `curl -k https://gitlab.haskell.org/haskell/ghcup-hs/-/raw/master/scripts/bootstrap/bootstrap-haskell | GHCUP_CURL_OPTS="-k" sh`
+2. Try to use wget instead: `wget -O /dev/stdout https://gitlab.haskell.org/haskell/ghcup-hs/-/raw/master/scripts/bootstrap/bootstrap-haskell | BOOTSTRAP_HASKELL_DOWNLOADER=wget sh`
+
+On windows, you can disable curl like so:
+
+```pwsh
+Set-ExecutionPolicy Bypass -Scope Process -Force;[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072;Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Invoke-WebRequest https://www.haskell.org/ghcup/sh/bootstrap-haskell.ps1 -UseBasicParsing))) -ArgumentList $true,$false,$false,$false,$false,$false,$false,"","","","",$true
+```
--- a/docs/index.md
+++ b/docs/index.md
@@ -57,7 +57,7 @@ hide:
 </section>

 <p id="help" class="ghcup-help">
-  Need help? Ask on
+  Need help? Check the <a href="guide/#troubleshooting">Troubleshooting section</a> or ask on
  <span>
    <a href="https://kiwiirc.com/nextclient/irc.libera.chat/?nick=Guest%7C?#haskell,#haskell-ghcup">
      <img src="irc.svg" alt="" />
--- a/docs/install.md
+++ b/docs/install.md
@@ -55,7 +55,10 @@ GHCup supports the following tools, which are also known as the **Haskell Toolch
 <table>
 <thead><tr><th>GHC Version</th><th>Tags</th></tr></thead>
 <tbody>
-<tr><td>9.2.2</td><td><span style="color:blue">latest</span>, base-4.16.1.0</td></tr>
+<tr><td>9.4.1</td><td><span style="color:blue">latest</span>, base-4.17.0.0</td></tr>
+<tr><td>9.2.4</td><td>base-4.16.3.0</td></tr>
+<tr><td>9.2.3</td><td>base-4.16.2.0</td></tr>
+<tr><td>9.2.2</td><td>base-4.16.1.0</td></tr>
 <tr><td>9.2.1</td><td>base-4.16.0.0</td></tr>
 <tr><td>9.0.2</td><td>base-4.15.1.0</td></tr>
 <tr><td>9.0.1</td><td>base-4.15.0.0</td></tr>
@@ -187,7 +190,7 @@ Lower availability of bindists. Stack and HLS binaries are experimental.
 Download the binary for your platform at [https://downloads.haskell.org/~ghcup/](https://downloads.haskell.org/~ghcup/)
 and place it into your `PATH` anywhere.

-If you want to GPG verify the binaries, import the following key first: `7784930957807690A66EBDBE3786C5262ECB4A3F`.
+If you want to GPG verify the binaries, import the following keys first: `7784930957807690A66EBDBE3786C5262ECB4A3F` and `FE5AB6C91FEA597C3B31180B73EDE9E8CFBAEF01`.

 Then adjust your `PATH` in `~/.bashrc` (or similar, depending on your shell) like so:

@@ -199,6 +202,16 @@ export PATH="$HOME/.cabal/bin:$HOME/.ghcup/bin:$PATH"

 See [ghcup.vim](https://github.com/hasufell/ghcup.vim).

+## VSCode integration
+The developers of the Haskell Language Server offer an [extension](https://github.com/haskell/vscode-haskell) tightly integrated with the [Haskell Language Server](https://github.com/haskell/haskell-language-server). To get started:
+
+1. Install GHCup. During installation, opt in to install the Haskell Language Server (HLS).
+2. Install the extension (from VSCode: Ctrl + P and then `ext install haskell.haskell`).
+3. Make sure your project uses the GHC version installed from GHCup (otherwise HLS is likely to fail on launch):
+    - instructions for [stack](https://docs.haskellstack.org/en/stable/yaml_configuration/#system-ghc)
+
+On Linux, some users have reported an issue when VSCode is not launched from a terminal ("cannot find ghc version"). A solution is to [let HLS know about your GHCup on $PATH](https://github.com/haskell/vscode-haskell#stackcabalghc-can-not-be-found).
+
 ## Get help

 * [Libera IRC chat on #haskell-ghcup or #haskell](https://kiwiirc.com/nextclient/irc.libera.chat/?nick=Guest%7C?#haskell,#haskell-ghcup)
--- a/docs/modules_small.svg
+++ b/docs/modules_small.svg
--- a/docs/modules_wide.svg
+++ b/docs/modules_wide.svg
--- a/docs/steps.md
+++ b/docs/steps.md
@@ -335,7 +335,7 @@ see the [Cabal user guide](https://cabal.readthedocs.io/en/stable/getting-starte

 To learn Haskell, try any of those:

- A beginner friendly [4-lectures course](https://github.com/haskell-beginners-2022/course-plan) with exercises (by [Kowainik](https://kowainik.github.io/))
+- A beginner friendly [4-lectures course](https://github.com/haskell-beginners-2022/course-plan) with exercises (by [Dmitrii Kovanikov](https://kodimensional.dev/))
 - An in-depth university [CIS 194 Haskell course](https://www.cis.upenn.edu/~cis194/spring13/) including exercises (by [Brent Yorgey](https://byorgey.wordpress.com/))

 ## Projects to contribute to
--- a/ghcup.cabal
+++ b/ghcup.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ghcup
-version:            0.1.17.7
+version:            0.1.18.1
 license:            LGPL-3.0-only
 license-file:       LICENSE
 copyright:          Julian Ospald 2020
@@ -21,6 +21,8 @@ extra-doc-files:
  README.md

 extra-source-files:
+  cbits/dirutils.c
+  cbits/dirutils.h
  data/build_mk/cross
  data/build_mk/default
  test/golden/GHCupInfo.json
@@ -44,38 +46,40 @@ flag internal-downloader
  manual:      True

 flag no-exe
-  description: Don't build any executables 
-  default:     False
-  manual:      True
-
-flag disable-upgrade
-  description:
-    Disable upgrade functionality. This is mainly to support brew packagers.
-
+  description: Don't build any executables
  default:     False
  manual:      True

 library
  exposed-modules:
    GHCup
+    GHCup.Cabal
    GHCup.Download
    GHCup.Download.Utils
    GHCup.Errors
+    GHCup.GHC
+    GHCup.HLS
+    GHCup.List
    GHCup.Platform
+    GHCup.Prelude
+    GHCup.Prelude.File
+    GHCup.Prelude.File.Search
+    GHCup.Prelude.Internal
+    GHCup.Prelude.Logger
+    GHCup.Prelude.Logger.Internal
+    GHCup.Prelude.MegaParsec
+    GHCup.Prelude.Process
+    GHCup.Prelude.String.QQ
+    GHCup.Prelude.Version.QQ
+    GHCup.Prompts
    GHCup.Requirements
+    GHCup.Stack
    GHCup.Types
    GHCup.Types.JSON
    GHCup.Types.JSON.Utils
    GHCup.Types.Optics
    GHCup.Utils
    GHCup.Utils.Dirs
-    GHCup.Utils.File
-    GHCup.Utils.File.Common
-    GHCup.Utils.Logger
-    GHCup.Utils.MegaParsec
-    GHCup.Utils.Prelude
-    GHCup.Utils.String.QQ
-    GHCup.Utils.Version.QQ
    GHCup.Version

  hs-source-dirs:     lib
@@ -107,8 +111,8 @@ library
    , base                  >=4.12       && <5
    , base16-bytestring     >=0.1.1.6    && <1.1
    , binary                ^>=0.8.6.0
-    , bytestring            ^>=0.10
-    , Cabal                 ^>=3.6.2.0
+    , bytestring            >=0.10       && <0.12
+    , Cabal                 ^>=3.0.0.0 || ^>=3.2.0.0 || ^>=3.4.0.0 || ^>=3.6.0.0
    , case-insensitive      ^>=1.2.1.0
    , casing                ^>=0.1.4.1
    , containers            ^>=0.6
@@ -116,6 +120,7 @@ library
    , deepseq               ^>=1.4.4.0
    , directory             ^>=1.3.6.0
    , disk-free-space       ^>=0.1.0.1
+    , exceptions            ^>=0.10
    , filepath              ^>=1.4.2.1
    , haskus-utils-types    ^>=1.5
    , haskus-utils-variant  ^>=3.2.1
@@ -133,6 +138,7 @@ library
    , safe                  ^>=0.3.18
    , safe-exceptions       ^>=0.1
    , split                 ^>=0.2.3.4
+    , streamly              ^>=0.8.2
    , strict-base           ^>=0.4
    , template-haskell      >=2.7        && <2.18
    , temporary             ^>=1.3
@@ -158,23 +164,30 @@ library
      , terminal-progress-bar  >=0.4.1

  if os(windows)
-    cpp-options:   -DIS_WINDOWS
+    cpp-options:     -DIS_WINDOWS
    other-modules:
-      GHCup.Utils.File.Windows
-      GHCup.Utils.Prelude.Windows
-      GHCup.Utils.Windows
+      GHCup.Prelude.File.Windows
+      GHCup.Prelude.Windows

+    -- GHCup.OptParse.Run uses this
+    exposed-modules: GHCup.Prelude.Process.Windows
    build-depends:
      , bzlib
      , process  ^>=1.6.11.0
-      , Win32    ^>=2.10
+      , Win32    >=2.10

  else
    other-modules:
-      GHCup.Utils.File.Posix
-      GHCup.Utils.Posix
-      GHCup.Utils.Prelude.Posix
+      GHCup.Prelude.File.Posix
+      GHCup.Prelude.File.Posix.Foreign
+      GHCup.Prelude.File.Posix.Traversals
+      GHCup.Prelude.Posix
+      GHCup.Prelude.Process.Posix

+    include-dirs:     cbits
+    includes:         dirutils.h
+    install-includes: dirutils.h
+    c-sources:        cbits/dirutils.c
    build-depends:
      , bz2              >=0.5.0.5 && <1.1
      , terminal-size    ^>=0.3.2.1
@@ -204,6 +217,7 @@ executable ghcup
    GHCup.OptParse.Set
    GHCup.OptParse.ToolRequirements
    GHCup.OptParse.UnSet
+    GHCup.OptParse.Upgrade
    GHCup.OptParse.Whereis

  hs-source-dirs:     app/ghcup
@@ -227,13 +241,14 @@ executable ghcup
    , aeson-pretty          ^>=0.8.8
    , async                 ^>=2.2.3
    , base                  >=4.12     && <5
-    , bytestring            ^>=0.10
+    , bytestring            >=0.10     && <0.12
    , cabal-plan            ^>=0.7.2
    , containers            ^>=0.6
    , deepseq               ^>=1.4
    , directory             ^>=1.3.6.0
    , filepath              ^>=1.4.2.1
    , ghcup
+    , haskus-utils-types    ^>=1.5
    , haskus-utils-variant  ^>=3.2.1
    , libarchive            ^>=3.0.3.0
    , megaparsec            >=8.0.0    && <9.3
@@ -277,12 +292,6 @@ executable ghcup
  if flag(no-exe)
    buildable: False

-  if flag(disable-upgrade)
-    cpp-options: -DDISABLE_UPGRADE
-
-  else
-    other-modules: GHCup.OptParse.Upgrade
-
 test-suite ghcup-test
  type:               exitcode-stdio-1.0
  main-is:            Main.hs
@@ -291,6 +300,7 @@ test-suite ghcup-test
  other-modules:
    GHCup.ArbitraryTypes
    GHCup.Types.JSONSpec
+    GHCup.Utils.FileSpec
    Spec

  default-language:   Haskell2010
@@ -308,14 +318,17 @@ test-suite ghcup-test

  build-depends:
    , base                      >=4.12    && <5
-    , bytestring                ^>=0.10
+    , bytestring                >=0.10    && <0.12
    , containers                ^>=0.6
-    , generic-arbitrary         >=0.1.0   && <0.3
+    , directory                 ^>=1.3.6.0
+    , filepath                  ^>=1.4.2.1
+    , generic-arbitrary         >=0.1.0   && <0.2.1 || >=0.2.2 && <0.3
    , ghcup
    , hspec                     >=2.7.10  && <2.10
    , hspec-golden-aeson        ^>=0.9
    , QuickCheck                ^>=2.14.1
    , quickcheck-arbitrary-adt  ^>=0.3.1.0
+    , streamly                  ^>=0.8.2
    , text                      ^>=1.2.4.0
    , uri-bytestring            ^>=0.3.2.2
    , versions                  >=4.0.1   && <5.1
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
--- a/lib/GHCup/Cabal.hs
+++ b/lib/GHCup/Cabal.hs
@@ -0,0 +1,284 @@
+{-# LANGUAGE CPP                   #-}
+{-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
+
+{-|
+Module      : GHCup.Cabal
+Description : GHCup installation functions for Cabal
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+-}
+module GHCup.Cabal where
+
+import           GHCup.Download
+import           GHCup.Errors
+import           GHCup.Types
+import           GHCup.Types.JSON               ( )
+import           GHCup.Types.Optics
+import           GHCup.Utils
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger
+
+import           Codec.Archive                  ( ArchiveResult )
+import           Control.Applicative
+import           Control.Exception.Safe
+import           Control.Monad
+#if !MIN_VERSION_base(4,13,0)
+import           Control.Monad.Fail             ( MonadFail )
+#endif
+import           Control.Monad.Reader
+import           Control.Monad.Trans.Resource
+                                         hiding ( throwM )
+import           Data.Either
+import           Data.List
+import           Data.Maybe
+import           Data.Versions                hiding ( patch )
+import           Haskus.Utils.Variant.Excepts
+import           Optics
+import           Prelude                 hiding ( abs
+                                                , writeFile
+                                                )
+import           Safe                    hiding ( at )
+import           System.FilePath
+import           System.IO.Error
+
+import qualified Data.Text                     as T
+import Text.PrettyPrint.HughesPJClass (prettyShow)
+
+
+
+    -------------------------
+    --[ Tool installation ]--
+    -------------------------
+
+
+-- | Like 'installCabalBin', except takes the 'DownloadInfo' as
+-- argument instead of looking it up from 'GHCupDownloads'.
+installCabalBindist :: ( MonadMask m
+                       , MonadCatch m
+                       , MonadReader env m
+                       , HasPlatformReq env
+                       , HasDirs env
+                       , HasSettings env
+                       , HasLog env
+                       , MonadResource m
+                       , MonadIO m
+                       , MonadUnliftIO m
+                       , MonadFail m
+                       )
+                    => DownloadInfo
+                    -> Version
+                    -> InstallDir
+                    -> Bool           -- ^ Force install
+                    -> Excepts
+                         '[ AlreadyInstalled
+                          , CopyError
+                          , DigestError
+                          , GPGError
+                          , DownloadFailed
+                          , NoDownload
+                          , NotInstalled
+                          , UnknownArchive
+                          , TarDirDoesNotExist
+                          , ArchiveResult
+                          , FileAlreadyExistsError
+                          ]
+                         m
+                         ()
+installCabalBindist dlinfo ver installDir forceInstall = do
+  lift $ logDebug $ "Requested to install cabal version " <> prettyVer ver
+
+  PlatformRequest {..} <- lift getPlatformReq
+  Dirs {..} <- lift getDirs
+
+  -- check if we already have a regular cabal already installed
+  regularCabalInstalled <- lift $ cabalInstalled ver
+
+  if
+    | not forceInstall
+    , regularCabalInstalled
+    , GHCupInternal <- installDir -> do
+        throwE $ AlreadyInstalled Cabal ver
+
+    | forceInstall
+    , regularCabalInstalled
+    , GHCupInternal <- installDir -> do
+        lift $ logInfo "Removing the currently installed version first!"
+        liftE $ rmCabalVer ver
+
+    | otherwise -> pure ()
+
+
+  -- download (or use cached version)
+  dl <- liftE $ downloadCached dlinfo Nothing
+
+  -- unpack
+  tmpUnpack <- lift withGHCupTmpDir
+  liftE $ cleanUpOnError tmpUnpack (unpackToDir (fromGHCupPath tmpUnpack) dl)
+  liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpUnpack)
+
+  -- the subdir of the archive where we do the work
+  workdir <- fromGHCupPath <$> maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
+
+  case installDir of
+    IsolateDir isoDir -> do             -- isolated install
+      lift $ logInfo $ "isolated installing Cabal to " <> T.pack isoDir
+      liftE $ installCabalUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
+
+    GHCupInternal -> do                 -- regular install
+      liftE $ installCabalUnpacked workdir (GHCupBinDir binDir) ver forceInstall
+
+
+-- | Install an unpacked cabal distribution.Symbol
+installCabalUnpacked :: (MonadCatch m, HasLog env, MonadIO m, MonadReader env m)
+              => FilePath      -- ^ Path to the unpacked cabal bindist (where the executable resides)
+              -> InstallDirResolved      -- ^ Path to install to
+              -> Version
+              -> Bool          -- ^ Force Install
+              -> Excepts '[CopyError, FileAlreadyExistsError] m ()
+installCabalUnpacked path inst ver forceInstall = do
+  lift $ logInfo "Installing cabal"
+  let cabalFile = "cabal"
+  liftIO $ createDirRecursive' (fromInstallDir inst)
+  let destFileName = cabalFile
+        <> (case inst of
+              IsolateDirResolved _ -> ""
+              _ -> ("-" <>) . T.unpack . prettyVer $ ver
+           )
+        <> exeExt
+  let destPath = fromInstallDir inst </> destFileName
+
+  copyFileE
+    (path </> cabalFile <> exeExt)
+    destPath
+    (not forceInstall)
+  lift $ chmod_755 destPath
+
+-- | Installs cabal into @~\/.ghcup\/bin/cabal-\<ver\>@ and
+-- creates a default @cabal -> cabal-x.y.z.q@ symlink for
+-- the latest installed version.
+installCabalBin :: ( MonadMask m
+                   , MonadCatch m
+                   , MonadReader env m
+                   , HasPlatformReq env
+                   , HasGHCupInfo env
+                   , HasDirs env
+                   , HasSettings env
+                   , HasLog env
+                   , MonadResource m
+                   , MonadIO m
+                   , MonadUnliftIO m
+                   , MonadFail m
+                   )
+                => Version
+                -> InstallDir
+                -> Bool           -- force install
+                -> Excepts
+                     '[ AlreadyInstalled
+                      , CopyError
+                      , DigestError
+                      , GPGError
+                      , DownloadFailed
+                      , NoDownload
+                      , NotInstalled
+                      , UnknownArchive
+                      , TarDirDoesNotExist
+                      , ArchiveResult
+                      , FileAlreadyExistsError
+                      ]
+                     m
+                     ()
+installCabalBin ver installDir forceInstall = do
+  dlinfo <- liftE $ getDownloadInfo Cabal ver
+  installCabalBindist dlinfo ver installDir forceInstall
+
+
+    -----------------
+    --[ Set cabal ]--
+    -----------------
+
+
+-- | Set the @~\/.ghcup\/bin\/cabal@ symlink.
+setCabal :: ( MonadMask m
+            , MonadReader env m
+            , HasDirs env
+            , HasLog env
+            , MonadFail m
+            , MonadIO m
+            , MonadUnliftIO m)
+         => Version
+         -> Excepts '[NotInstalled] m ()
+setCabal ver = do
+  let targetFile = "cabal-" <> T.unpack (prettyVer ver) <> exeExt
+
+  -- symlink destination
+  Dirs {..} <- lift getDirs
+
+  whenM (liftIO $ not <$> doesFileExist (binDir </> targetFile))
+    $ throwE
+    $ NotInstalled Cabal (GHCTargetVersion Nothing ver)
+
+  let cabalbin = binDir </> "cabal" <> exeExt
+
+  -- create link
+  let destL = targetFile
+  lift $ createLink destL cabalbin
+
+  liftIO (isShadowed cabalbin) >>= \case
+    Nothing -> pure ()
+    Just pa -> lift $ logWarn $ T.pack $ prettyShow (ToolShadowed Cabal pa cabalbin ver)
+
+  pure ()
+
+unsetCabal :: ( MonadMask m
+              , MonadReader env m
+              , HasDirs env
+              , MonadIO m)
+           => m ()
+unsetCabal = do
+  Dirs {..} <- getDirs
+  let cabalbin = binDir </> "cabal" <> exeExt
+  hideError doesNotExistErrorType $ rmLink cabalbin
+
+
+    ----------------
+    --[ Rm cabal ]--
+    ----------------
+
+
+-- | Delete a cabal version. Will try to fix the @cabal@ symlink
+-- after removal (e.g. setting it to an older version).
+rmCabalVer :: ( MonadMask m
+              , MonadReader env m
+              , HasDirs env
+              , MonadThrow m
+              , HasLog env
+              , MonadIO m
+              , MonadFail m
+              , MonadCatch m
+              , MonadUnliftIO m
+              )
+           => Version
+           -> Excepts '[NotInstalled] m ()
+rmCabalVer ver = do
+  whenM (lift $ fmap not $ cabalInstalled ver) $ throwE (NotInstalled Cabal (GHCTargetVersion Nothing ver))
+
+  cSet      <- lift cabalSet
+
+  Dirs {..} <- lift getDirs
+
+  let cabalFile = "cabal-" <> T.unpack (prettyVer ver) <> exeExt
+  lift $ hideError doesNotExistErrorType $ recycleFile (binDir </> cabalFile)
+
+  when (Just ver == cSet) $ do
+    cVers <- lift $ fmap rights getInstalledCabals
+    case headMay . reverse . sort $ cVers of
+      Just latestver -> setCabal latestver
+      Nothing        -> lift $ rmLink (binDir </> "cabal" <> exeExt)
--- a/lib/GHCup/Download.hs
+++ b/lib/GHCup/Download.hs
@@ -34,9 +34,10 @@ import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Types.JSON               ( )
 import           GHCup.Utils.Dirs
-import           GHCup.Utils.File
-import           GHCup.Utils.Logger
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger.Internal
+import           GHCup.Prelude.Process
 import           GHCup.Version

 import           Control.Applicative
@@ -69,7 +70,6 @@ import           Prelude                 hiding ( abs
                                                , writeFile
                                                )
 import           Safe
-import           System.Directory
 import           System.Environment
 import           System.Exit
 import           System.FilePath
@@ -145,7 +145,7 @@ getDownloadsF = do
 yamlFromCache :: (MonadReader env m, HasDirs env) => URI -> m FilePath
 yamlFromCache uri = do
  Dirs{..} <- getDirs
-  pure (cacheDir </> (T.unpack . decUTF8Safe . urlBaseName . view pathL' $ uri))
+  pure (fromGHCupPath cacheDir </> (T.unpack . decUTF8Safe . urlBaseName . view pathL' $ uri))


 etagsFile :: FilePath -> FilePath
@@ -242,7 +242,7 @@ getBase uri = do
    Settings { metaCache } <- lift getSettings

       -- for local files, let's short-circuit and ignore access time
-    if | scheme == "file" -> liftE $ download uri' Nothing Nothing cacheDir Nothing True
+    if | scheme == "file" -> liftE $ download uri' Nothing Nothing (fromGHCupPath cacheDir) Nothing True
       | e -> do
          accessTime <- fmap utcTimeToPOSIXSeconds $ liftIO $ getAccessTime json_file
          let sinceLastAccess = utcTimeToPOSIXSeconds currentTime - accessTime
@@ -581,7 +581,7 @@ downloadCached dli mfn = do
    True -> downloadCached' dli mfn Nothing
    False -> do
      tmp <- lift withGHCupTmpDir
-      liftE $ download (_dlUri dli) Nothing (Just (_dlHash dli)) tmp mfn False
+      liftE $ download (_dlUri dli) Nothing (Just (_dlHash dli)) (fromGHCupPath tmp) mfn False


 downloadCached' :: ( MonadReader env m
@@ -599,7 +599,7 @@ downloadCached' :: ( MonadReader env m
                -> Excepts '[DigestError , DownloadFailed, GPGError] m FilePath
 downloadCached' dli mfn mDestDir = do
  Dirs { cacheDir } <- lift getDirs
-  let destDir = fromMaybe cacheDir mDestDir
+  let destDir = fromMaybe (fromGHCupPath cacheDir) mDestDir
  let fn = fromMaybe ((T.unpack . decUTF8Safe) $ urlBaseName $ view (dlUri % pathL') dli) mfn
  let cachfile = destDir </> fn
  fileExists <- liftIO $ doesFileExist cachfile
--- a/lib/GHCup/Download/IOStreams.hs
+++ b/lib/GHCup/Download/IOStreams.hs
@@ -10,7 +10,7 @@ module GHCup.Download.IOStreams where
 import           GHCup.Download.Utils
 import           GHCup.Errors
 import           GHCup.Types.JSON               ( )
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude

 import           Control.Applicative
 import           Control.Exception.Safe
--- a/lib/GHCup/Download/Utils.hs
+++ b/lib/GHCup/Download/Utils.hs
@@ -10,7 +10,7 @@ module GHCup.Download.Utils where
 import           GHCup.Errors
 import           GHCup.Types.Optics
 import           GHCup.Types.JSON               ( )
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude

 import           Control.Applicative
 import           Control.Monad
--- a/lib/GHCup/Errors.hs
+++ b/lib/GHCup/Errors.hs
@@ -27,6 +27,7 @@ import           Data.CaseInsensitive           ( CI )
 import           Data.Text                      ( Text )
 import           Data.Versions
 import           Haskus.Utils.Variant
+import           System.FilePath
 import           Text.PrettyPrint               hiding ( (<>) )
 import           Text.PrettyPrint.HughesPJClass hiding ( (<>) )
 import           URI.ByteString
@@ -104,6 +105,15 @@ instance Pretty CopyError where
  pPrint (CopyError reason) =
    text ("Unable to copy a file. Reason was: " ++ reason)

+-- | Unable to merge file trees.
+data MergeFileTreeError = MergeFileTreeError IOException FilePath FilePath
+  deriving Show
+
+instance Pretty MergeFileTreeError where
+  pPrint (MergeFileTreeError e from to) =
+    text "Failed to merge file tree from" <+> text from <+> text "to" <+> text to <+> text "\nexception was:" <+> text (displayException e)
+     <+> text "\n...you may need to delete" <+> text to <+> text "manually. Make sure it's gone."
+
 -- | Unable to find a tag of a tool.
 data TagNotFound = TagNotFound Tag Tool
  deriving Show
@@ -127,10 +137,13 @@ data AlreadyInstalled = AlreadyInstalled Tool Version

 instance Pretty AlreadyInstalled where
  pPrint (AlreadyInstalled tool ver') =
-    pPrint tool <+> text "-" <+> pPrint ver' <+> text "is already installed"
+    (pPrint tool <> text "-" <> pPrint ver') <+> text "is already installed;"
+    <+> text "if you really want to reinstall it, you may want to run 'ghcup install" <+> pPrint tool <+> text "--force" <+> (pPrint ver' <> text "'")
+

 -- | The Directory is supposed to be empty, but wasn't.
 data DirNotEmpty = DirNotEmpty {path :: FilePath}
+  deriving Show

 instance Pretty DirNotEmpty where
  pPrint (DirNotEmpty path) = do
@@ -145,6 +158,13 @@ instance Pretty NotInstalled where
  pPrint (NotInstalled tool ver) =
    text "The version" <+> pPrint ver <+> text "of the tool" <+> pPrint tool <+> text "is not installed."

+data UninstallFailed = UninstallFailed FilePath [FilePath]
+  deriving Show
+
+instance Pretty UninstallFailed where
+  pPrint (UninstallFailed dir files) =
+    text "The following files survived uninstallation: " <+> pPrint files <+> text "...consider removing" <+> pPrint dir <+> text "manually."
+
 -- | An executable was expected to be in PATH, but was not found.
 data NotFoundInPATH = NotFoundInPATH FilePath
  deriving Show
@@ -291,6 +311,26 @@ instance Pretty HadrianNotFound where
  pPrint HadrianNotFound =
    text "Could not find Hadrian build files. Does this GHC version support Hadrian builds?"

+data ToolShadowed = ToolShadowed
+                       Tool
+                       FilePath  -- shadow binary
+                       FilePath  -- upgraded binary
+                       Version   -- upgraded version
+  deriving Show
+
+instance Pretty ToolShadowed where
+  pPrint (ToolShadowed tool sh up _) =
+    text (prettyShow tool
+         <> " is shadowed by "
+         <> sh
+         <> ".\nThe upgrade will not be in effect, unless you remove "
+         <> sh
+         <> "\nor make sure "
+         <> takeDirectory up
+         <> " comes before "
+         <> takeDirectory sh
+         <> " in PATH."
+         )

    -------------------------
    --[ High-level errors ]--
@@ -307,6 +347,17 @@ instance Pretty DownloadFailed where

 deriving instance Show DownloadFailed

+data InstallSetError = forall xs1 xs2 . (Show (V xs1), Pretty (V xs1), Show (V xs2), Pretty (V xs2)) => InstallSetError (V xs1) (V xs2)
+
+instance Pretty InstallSetError where
+  pPrint (InstallSetError reason1 reason2) =
+     text "Both installation and setting the tool failed. Install error was:"
+      <+> pPrint reason1
+      <+> text "\nSet error was:"
+      <+> pPrint reason2
+
+deriving instance Show InstallSetError
+

 -- | A build failed.
 data BuildFailed = forall es . (ToVariantMaybe BuildFailed es, PopVariant BuildFailed es, Pretty (V es), Show (V es)) => BuildFailed FilePath (V es)
--- a/lib/GHCup/GHC.hs
+++ b/lib/GHCup/GHC.hs
--- a/lib/GHCup/HLS.hs
+++ b/lib/GHCup/HLS.hs
@@ -0,0 +1,723 @@
+{-# LANGUAGE CPP                   #-}
+{-# LANGUAGE BangPatterns          #-}
+{-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
+{-# LANGUAGE QuasiQuotes           #-}
+
+{-|
+Module      : GHCup.HLS
+Description : GHCup installation functions for HLS
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+-}
+module GHCup.HLS where
+
+import           GHCup.Download
+import           GHCup.Errors
+import           GHCup.Types
+import           GHCup.Types.JSON               ( )
+import           GHCup.Types.Optics
+import           GHCup.Utils
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.Process
+import           GHCup.Prelude.String.QQ
+
+import           Codec.Archive                  ( ArchiveResult )
+import           Control.Applicative
+import           Control.Exception.Safe
+import           Control.Monad
+#if !MIN_VERSION_base(4,13,0)
+import           Control.Monad.Fail             ( MonadFail )
+#endif
+import           Control.Monad.Reader
+import           Control.Monad.Trans.Resource
+                                         hiding ( throwM )
+import           Data.ByteString                ( ByteString )
+import           Data.Either
+import           Data.List
+import           Data.Maybe
+import           Data.String                    ( fromString )
+import           Data.Text                      ( Text )
+import           Data.Versions                hiding ( patch )
+import           Distribution.Types.Version   hiding ( Version )
+import           Distribution.Types.PackageId
+import           Distribution.Types.PackageDescription
+import           Distribution.Types.GenericPackageDescription
+import           Distribution.PackageDescription.Parsec
+import           GHC.IO.Exception
+import           Haskus.Utils.Variant.Excepts
+import           Optics
+import           Prelude                 hiding ( abs
+                                                , writeFile
+                                                )
+import           Safe                    hiding ( at )
+import           System.FilePath
+import           System.IO.Error
+import           Text.Regex.Posix
+import           URI.ByteString
+
+import qualified Data.List.NonEmpty            as NE
+import qualified Data.ByteString               as B
+import qualified Data.Text                     as T
+import qualified Text.Megaparsec               as MP
+import Text.PrettyPrint.HughesPJClass (prettyShow)
+
+
+data HLSVer = SourceDist Version
+            | GitDist GitBranch
+            | HackageDist Version
+            | RemoteDist URI
+
+
+
+    --------------------
+    --[ Installation ]--
+    --------------------
+
+
+-- | Like 'installHLSBin, except takes the 'DownloadInfo' as
+-- argument instead of looking it up from 'GHCupDownloads'.
+installHLSBindist :: ( MonadMask m
+                     , MonadCatch m
+                     , MonadReader env m
+                     , HasPlatformReq env
+                     , HasDirs env
+                     , HasSettings env
+                     , HasLog env
+                     , MonadResource m
+                     , MonadIO m
+                     , MonadUnliftIO m
+                     , MonadFail m
+                     )
+                  => DownloadInfo
+                  -> Version
+                  -> InstallDir -- ^ isolated install path, if user passed any
+                  -> Bool       -- ^ Force install
+                  -> Excepts
+                       '[ AlreadyInstalled
+                        , CopyError
+                        , DigestError
+                        , GPGError
+                        , DownloadFailed
+                        , NoDownload
+                        , NotInstalled
+                        , UnknownArchive
+                        , TarDirDoesNotExist
+                        , ArchiveResult
+                        , FileAlreadyExistsError
+                        , ProcessError
+                        , DirNotEmpty
+                        , UninstallFailed
+                        , MergeFileTreeError
+                        ]
+                       m
+                       ()
+installHLSBindist dlinfo ver installDir forceInstall = do
+  lift $ logDebug $ "Requested to install hls version " <> prettyVer ver
+
+  PlatformRequest {..} <- lift getPlatformReq
+  Dirs {..} <- lift getDirs
+
+  regularHLSInstalled <- lift $ hlsInstalled ver
+
+  if
+    | not forceInstall
+    , regularHLSInstalled
+    , GHCupInternal <- installDir -> do        -- regular install
+        throwE $ AlreadyInstalled HLS ver
+
+    | forceInstall
+    , regularHLSInstalled
+    , GHCupInternal <- installDir -> do        -- regular forced install
+        lift $ logInfo "Removing the currently installed version of HLS before force installing!"
+        liftE $ rmHLSVer ver
+
+    | otherwise -> pure ()
+
+  -- download (or use cached version)
+  dl <- liftE $ downloadCached dlinfo Nothing
+
+  -- unpack
+  tmpUnpack <- lift withGHCupTmpDir
+  liftE $ cleanUpOnError tmpUnpack (unpackToDir (fromGHCupPath tmpUnpack) dl)
+  liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpUnpack)
+
+  -- the subdir of the archive where we do the work
+  workdir <- fromGHCupPath <$> maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
+  legacy <- liftIO $ isLegacyHLSBindist workdir
+
+  if
+    | not forceInstall
+    , not legacy
+    , (IsolateDir fp) <- installDir -> liftE $ installDestSanityCheck (IsolateDirResolved fp)
+    | otherwise -> pure ()
+
+  case installDir of
+    IsolateDir isoDir -> do
+      lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
+      if legacy
+      then liftE $ installHLSUnpackedLegacy workdir (IsolateDirResolved isoDir) ver forceInstall
+      else liftE $ runBuildAction tmpUnpack $ installHLSUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
+
+    GHCupInternal -> do
+      if legacy
+      then liftE $ installHLSUnpackedLegacy workdir (GHCupBinDir binDir) ver forceInstall
+      else do
+        inst <- ghcupHLSDir ver
+        liftE $ runBuildAction tmpUnpack
+              $ installHLSUnpacked workdir (GHCupDir inst) ver forceInstall
+        liftE $ setHLS ver SetHLS_XYZ Nothing
+
+
+isLegacyHLSBindist :: FilePath -- ^ Path to the unpacked hls bindist
+                   -> IO Bool
+isLegacyHLSBindist path = do
+  not <$> doesFileExist (path </> "GNUmakefile")
+
+-- | Install an unpacked hls distribution.
+installHLSUnpacked :: ( MonadMask m
+                      , MonadUnliftIO m
+                      , MonadReader env m
+                      , MonadFail m
+                      , HasLog env
+                      , HasDirs env
+                      , HasSettings env
+                      , MonadCatch m
+                      , MonadIO m
+                      , MonadResource m
+                      , HasPlatformReq env
+                      )
+                   => FilePath      -- ^ Path to the unpacked hls bindist (where the executable resides)
+                   -> InstallDirResolved      -- ^ Path to install to
+                   -> Version
+                   -> Bool
+                   -> Excepts '[ProcessError, CopyError, FileAlreadyExistsError, NotInstalled, MergeFileTreeError] m ()
+installHLSUnpacked path inst ver forceInstall = do
+  PlatformRequest { .. } <- lift getPlatformReq
+  lift $ logInfo "Installing HLS"
+  tmpInstallDest <- lift withGHCupTmpDir
+  lEM $ make ["DESTDIR=" <> fromGHCupPath tmpInstallDest, "PREFIX=" <> fromInstallDir inst, "install"] (Just path)
+  liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpInstallDest)
+  liftE $ mergeFileTree (tmpInstallDest `appendGHCupPath` dropDrive (fromInstallDir inst))
+                   inst
+                   HLS
+                   (mkTVer ver)
+                   (\f t -> liftIO $ do
+                       mtime <- ifM (pathIsSymbolicLink f) (pure Nothing) (Just <$> getModificationTime f)
+                       install f t (not forceInstall)
+                       forM_ mtime $ setModificationTime t)
+
+-- | Install an unpacked hls distribution (legacy).
+installHLSUnpackedLegacy :: (MonadReader env m, MonadFail m, HasLog env, MonadCatch m, MonadIO m)
+                         => FilePath      -- ^ Path to the unpacked hls bindist (where the executable resides)
+                         -> InstallDirResolved      -- ^ Path to install to
+                         -> Version
+                         -> Bool          -- ^ is it a force install
+                         -> Excepts '[CopyError, FileAlreadyExistsError] m ()
+installHLSUnpackedLegacy path installDir ver forceInstall = do
+  lift $ logInfo "Installing HLS"
+  liftIO $ createDirRecursive' (fromInstallDir installDir)
+
+  -- install haskell-language-server-<ghcver>
+  bins@(_:_) <- liftIO $ findFiles
+    path
+    (makeRegexOpts compExtended
+                   execBlank
+                   ([s|^haskell-language-server-[0-9].*$|] :: ByteString)
+    )
+  forM_ bins $ \f -> do
+    let toF = dropSuffix exeExt f
+              <> (case installDir of
+                   IsolateDirResolved _ -> ""
+                   _ -> ("~" <>) . T.unpack . prettyVer $ ver
+                 )
+              <> exeExt
+
+    let srcPath = path </> f
+    let destPath = fromInstallDir installDir </> toF
+
+    -- destination could be an existing symlink
+    -- for new make-based HLSes
+    liftIO $ rmFileForce destPath
+
+    copyFileE
+      srcPath
+      destPath
+      (not forceInstall)
+    lift $ chmod_755 destPath
+
+  -- install haskell-language-server-wrapper
+  let wrapper = "haskell-language-server-wrapper"
+      toF = wrapper
+            <> (case installDir of
+                 IsolateDirResolved _ -> ""
+                 _ -> ("-" <>) . T.unpack . prettyVer $ ver
+               )
+            <> exeExt
+      srcWrapperPath = path </> wrapper <> exeExt
+      destWrapperPath = fromInstallDir installDir </> toF
+
+  liftIO $ rmFileForce destWrapperPath
+  copyFileE
+    srcWrapperPath
+    destWrapperPath
+    (not forceInstall)
+
+  lift $ chmod_755 destWrapperPath
+
+
+
+-- | Installs hls binaries @haskell-language-server-\<ghcver\>@
+-- into @~\/.ghcup\/bin/@, as well as @haskell-languager-server-wrapper@.
+installHLSBin :: ( MonadMask m
+                 , MonadCatch m
+                 , MonadReader env m
+                 , HasPlatformReq env
+                 , HasGHCupInfo env
+                 , HasDirs env
+                 , HasSettings env
+                 , HasLog env
+                 , MonadResource m
+                 , MonadIO m
+                 , MonadUnliftIO m
+                 , MonadFail m
+                 )
+              => Version
+              -> InstallDir
+              -> Bool            -- force install
+              -> Excepts
+                   '[ AlreadyInstalled
+                    , CopyError
+                    , DigestError
+                    , GPGError
+                    , DownloadFailed
+                    , NoDownload
+                    , NotInstalled
+                    , UnknownArchive
+                    , TarDirDoesNotExist
+                    , ArchiveResult
+                    , FileAlreadyExistsError
+                    , ProcessError
+                    , DirNotEmpty
+                    , UninstallFailed
+                    , MergeFileTreeError
+                    ]
+                   m
+                   ()
+installHLSBin ver installDir forceInstall = do
+  dlinfo <- liftE $ getDownloadInfo HLS ver
+  installHLSBindist dlinfo ver installDir forceInstall
+
+
+compileHLS :: ( MonadMask m
+              , MonadCatch m
+              , MonadReader env m
+              , HasDirs env
+              , HasSettings env
+              , HasPlatformReq env
+              , HasGHCupInfo env
+              , HasLog env
+              , MonadResource m
+              , MonadIO m
+              , MonadUnliftIO m
+              , MonadFail m
+              )
+           => HLSVer
+           -> [Version]
+           -> Maybe Int
+           -> Either Bool Version
+           -> InstallDir
+           -> Maybe (Either FilePath URI)
+           -> Maybe URI
+           -> Bool
+           -> Maybe (Either FilePath [URI])  -- ^ patches
+           -> [Text]                   -- ^ additional args to cabal install
+           -> Excepts '[ NoDownload
+                       , GPGError
+                       , DownloadFailed
+                       , DigestError
+                       , UnknownArchive
+                       , TarDirDoesNotExist
+                       , ArchiveResult
+                       , BuildFailed
+                       , NotInstalled
+                       ] m Version
+compileHLS targetHLS ghcs jobs ov installDir cabalProject cabalProjectLocal updateCabal patches cabalArgs = do
+  PlatformRequest { .. } <- lift getPlatformReq
+  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
+  Dirs { .. } <- lift getDirs
+
+  when updateCabal $ reThrowAll @_ @'[ProcessError] DownloadFailed $ do
+    lift $ logInfo "Updating cabal DB"
+    lEM $ exec "cabal" ["update"] (Just $ fromGHCupPath tmpDir) Nothing
+
+  (workdir, tmpUnpack, tver, git_describe) <- case targetHLS of
+    -- unpack from version tarball
+    SourceDist tver -> do
+      lift $ logDebug $ "Requested to compile: " <> prettyVer tver
+
+      -- download source tarball
+      dlInfo <-
+        preview (ix HLS % ix tver % viSourceDL % _Just) dls
+          ?? NoDownload
+      dl <- liftE $ downloadCached dlInfo Nothing
+
+      -- unpack
+      tmpUnpack <- lift mkGhcupTmpDir
+      liftE $ cleanUpOnError tmpUnpack (unpackToDir (fromGHCupPath tmpUnpack) dl)
+      liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpUnpack)
+
+      workdir <- maybe (pure tmpUnpack)
+                       (liftE . intoSubdir tmpUnpack)
+                       (view dlSubdir dlInfo)
+
+      pure (workdir, tmpUnpack, tver, Nothing)
+
+    HackageDist tver -> do
+      lift $ logDebug $ "Requested to compile (from hackage): " <> prettyVer tver
+
+      -- download source tarball
+      tmpUnpack <- lift mkGhcupTmpDir
+      let hls = "haskell-language-server-" <> T.unpack (prettyVer tver)
+      reThrowAll @_ @'[ProcessError] DownloadFailed $ do
+        -- unpack
+        lEM $ exec "cabal" ["unpack", hls] (Just $ fromGHCupPath tmpUnpack) Nothing
+
+      let workdir = appendGHCupPath tmpUnpack hls
+
+      pure (workdir, tmpUnpack, tver, Nothing)
+
+    RemoteDist uri -> do
+      lift $ logDebug $ "Requested to compile (from uri): " <> T.pack (show uri)
+
+      -- download source tarball
+      tmpDownload <- lift withGHCupTmpDir
+      tmpUnpack <- lift mkGhcupTmpDir
+      tar <- liftE $ download uri Nothing Nothing (fromGHCupPath tmpDownload) Nothing False
+      (cf, tver) <- liftE $ cleanUpOnError tmpUnpack $ do
+        unpackToDir (fromGHCupPath tmpUnpack) tar
+        let regex = [s|^(.*/)*haskell-language-server\.cabal$|] :: B.ByteString
+        [cabalFile] <- liftIO $ findFilesDeep
+          tmpUnpack
+          (makeRegexOpts compExtended
+                         execBlank
+                         regex
+          )
+        tver <- getCabalVersion (fromGHCupPath tmpUnpack </> cabalFile)
+        pure (cabalFile, tver)
+
+      let workdir = appendGHCupPath tmpUnpack (takeDirectory cf)
+
+      pure (workdir, tmpUnpack, tver, Nothing)
+
+    -- clone from git
+    GitDist GitBranch{..} -> do
+      tmpUnpack <- lift mkGhcupTmpDir
+      let git args = execLogged "git" ("--no-pager":args) (Just $ fromGHCupPath tmpUnpack) "git" Nothing
+      reThrowAll @_ @'[ProcessError] DownloadFailed $ do
+        let rep = fromMaybe "https://github.com/haskell/haskell-language-server.git" repo
+        lift $ logInfo $ "Fetching git repo " <> T.pack rep <> " at ref " <> T.pack ref <> " (this may take a while)"
+        lEM $ git [ "init" ]
+        lEM $ git [ "remote"
+                  , "add"
+                  , "origin"
+                  , fromString rep ]
+
+        -- figure out if we can do a shallow clone
+        remoteBranches <- catchE @ProcessError @'[ProcessError] @'[] (\_ -> pure [])
+            $ fmap processBranches $ gitOut ["ls-remote", "--heads", "origin"] (fromGHCupPath tmpUnpack)
+        let shallow_clone
+              | gitDescribeRequested                 = False
+              | isCommitHash ref                     = True
+              | fromString ref `elem` remoteBranches = True
+              | otherwise                            = False
+
+        lift $ logDebug $ "Shallow clone: " <> T.pack (show shallow_clone)
+
+        -- fetch
+        let fetch_args
+              | shallow_clone = ["fetch", "--depth", "1", "--quiet", "origin", fromString ref]
+              | otherwise     = ["fetch", "--tags",       "--quiet", "origin"                ]
+        lEM $ git fetch_args
+
+        -- checkout
+        lEM $ git [ "checkout", fromString ref ]
+
+        -- gather some info
+        git_describe <- if shallow_clone
+                        then pure Nothing
+                        else fmap Just $ gitOut ["describe", "--tags"] (fromGHCupPath tmpUnpack)
+        chash <- gitOut ["rev-parse", "HEAD" ] (fromGHCupPath tmpUnpack)
+        tver <- getCabalVersion (fromGHCupPath tmpUnpack </> "haskell-language-server.cabal")
+
+        liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpUnpack)
+        lift $ logInfo $ "Examining git ref " <> T.pack ref <> "\n  " <>
+                                    "HLS version (from cabal file): " <> prettyVer tver <>
+                                    (if not shallow_clone then "\n  " <> "'git describe' output: " <> fromJust git_describe else mempty) <>
+                                    (if isCommitHash ref then mempty else "\n  " <> "commit hash: " <> chash)
+
+        pure (tmpUnpack, tmpUnpack, tver, git_describe)
+
+  -- the version that's installed may differ from the
+  -- compiled version, so the user can overwrite it
+  installVer <- case ov of
+                  Left True -> case git_describe of
+                                 -- git describe
+                                 Just h -> either (fail . displayException) pure . version $ h
+                                 -- git describe, but not building from git, lol
+                                 Nothing -> pure tver
+                  -- default: use detected version
+                  Left False -> pure tver
+                  -- overwrite version with users value
+                  Right v -> pure v
+
+  liftE $ runBuildAction
+    tmpUnpack
+    (reThrowAll @_ @'[GPGError, DownloadFailed, DigestError, PatchFailed, ProcessError, FileAlreadyExistsError, CopyError] @'[BuildFailed] (BuildFailed $ fromGHCupPath workdir) $ do
+      let tmpInstallDir = fromGHCupPath workdir </> "out"
+      liftIO $ createDirRecursive' tmpInstallDir
+
+      -- apply patches
+      liftE $ applyAnyPatch patches (fromGHCupPath workdir)
+
+      -- set up project files
+      cp <- case cabalProject of
+        Just (Left cp)
+          | isAbsolute cp -> do
+              copyFileE cp (fromGHCupPath workdir </> "cabal.project") False
+              pure "cabal.project"
+          | otherwise -> pure (takeFileName cp)
+        Just (Right uri) -> do
+          tmpUnpack' <- lift withGHCupTmpDir
+          cp <- liftE $ download uri Nothing Nothing (fromGHCupPath tmpUnpack') (Just "cabal.project") False
+          copyFileE cp (fromGHCupPath workdir </> "cabal.project") False
+          pure "cabal.project"
+        Nothing
+          | HackageDist _ <- targetHLS -> do
+              liftIO $ B.writeFile (fromGHCupPath workdir </> "cabal.project") "packages: ./"
+              pure "cabal.project"
+          | RemoteDist _ <- targetHLS -> do
+              let cabalFile = fromGHCupPath workdir </> "cabal.project"
+              liftIO $ whenM (not <$> doesFileExist cabalFile) $ B.writeFile cabalFile "packages: ./"
+              pure "cabal.project"
+          | otherwise -> pure "cabal.project"
+      forM_ cabalProjectLocal $ \uri -> do
+        tmpUnpack' <- lift withGHCupTmpDir
+        cpl <- liftE $ download uri Nothing Nothing (fromGHCupPath tmpUnpack') (Just (cp <.> "local")) False
+        copyFileE cpl (fromGHCupPath workdir </> cp <.> "local") False
+      artifacts <- forM (sort ghcs) $ \ghc -> do
+        let ghcInstallDir = tmpInstallDir </> T.unpack (prettyVer ghc)
+        liftIO $ createDirRecursive' tmpInstallDir
+        lift $ logInfo $ "Building HLS " <> prettyVer installVer <> " for GHC version " <> prettyVer ghc
+        liftE $ lEM @_ @'[ProcessError] $
+          execLogged "cabal" ( [ "v2-install"
+                               , "-w"
+                               , "ghc-" <> T.unpack (prettyVer ghc)
+                               , "--install-method=copy"
+                               ] ++
+                               maybe [] (\j -> ["--jobs=" <> show j]) jobs ++
+                               [ "--overwrite-policy=always"
+                               , "--disable-profiling"
+                               , "--disable-tests"
+                               , "--installdir=" <> ghcInstallDir
+                               , "--project-file=" <> cp
+                               ] ++ fmap T.unpack cabalArgs ++ [
+                                 "exe:haskell-language-server"
+                               , "exe:haskell-language-server-wrapper"]
+                             )
+                             (Just $ fromGHCupPath workdir)
+                             "cabal"
+                             Nothing
+        pure ghcInstallDir
+
+      forM_ artifacts $ \artifact -> do
+        logDebug $ T.pack (show artifact)
+        liftIO $ renameFile (artifact </> "haskell-language-server" <.> exeExt)
+          (tmpInstallDir </> "haskell-language-server-" <> takeFileName artifact <.> exeExt)
+        liftIO $ renameFile (artifact </> "haskell-language-server-wrapper" <.> exeExt)
+          (tmpInstallDir </> "haskell-language-server-wrapper" <.> exeExt)
+
+      case installDir of
+        IsolateDir isoDir -> do
+          lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (IsolateDirResolved isoDir) installVer True
+        GHCupInternal -> do
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (GHCupBinDir binDir) installVer True
+    )
+
+  pure installVer
+ where
+  gitDescribeRequested = case ov of
+                           Left b -> b
+                           _      -> False
+
+
+    -----------------
+    --[ Set/Unset ]--
+    -----------------
+
+-- | Set the haskell-language-server symlinks.
+setHLS :: ( MonadReader env m
+          , HasDirs env
+          , HasLog env
+          , MonadIO m
+          , MonadMask m
+          , MonadFail m
+          , MonadUnliftIO m
+          )
+       => Version
+       -> SetHLS
+       -> Maybe FilePath  -- if set, signals that we're not operating in ~/.ghcup/bin
+                          -- and don't want mess with other versions
+       -> Excepts '[NotInstalled] m ()
+setHLS ver shls mBinDir = do
+  whenM (lift $ not <$> hlsInstalled ver) (throwE (NotInstalled HLS (GHCTargetVersion Nothing ver)))
+
+  -- symlink destination
+  binDir <- case mBinDir of
+    Just x -> pure x
+    Nothing -> do
+      Dirs {binDir = f} <- lift getDirs
+      pure f
+
+  -- first delete the old symlinks
+  when (isNothing mBinDir) $
+    case shls of
+      -- not for legacy
+      SetHLS_XYZ -> liftE $ rmMinorHLSSymlinks ver
+      -- legacy and new
+      SetHLSOnly -> liftE rmPlainHLS
+
+  case shls of
+    -- not for legacy
+    SetHLS_XYZ -> do
+      bins <- lift $ hlsInternalServerScripts ver Nothing
+
+      forM_ bins $ \f -> do
+        let fname = takeFileName f
+        destL <- binarySymLinkDestination binDir f
+        let target = if "haskell-language-server-wrapper" `isPrefixOf` fname
+                     then fname <> "-" <> T.unpack (prettyVer ver) <> exeExt
+                     else fname <> "~" <> T.unpack (prettyVer ver) <> exeExt
+        lift $ createLink destL (binDir </> target)
+
+    -- legacy and new
+    SetHLSOnly -> do
+      -- set haskell-language-server-<ghcver> symlinks
+      bins <- lift $ hlsServerBinaries ver Nothing
+      when (null bins) $ throwE $ NotInstalled HLS (GHCTargetVersion Nothing ver)
+
+      forM_ bins $ \f -> do
+        let destL = f
+        let target = (<> exeExt) . head . splitOn "~" $ f
+        lift $ createLink destL (binDir </> target)
+
+      -- set haskell-language-server-wrapper symlink
+      let destL = "haskell-language-server-wrapper-" <> T.unpack (prettyVer ver) <> exeExt
+      let wrapper = binDir </> "haskell-language-server-wrapper" <> exeExt
+
+      lift $ createLink destL wrapper
+
+      when (isNothing mBinDir) $
+        lift warnAboutHlsCompatibility
+
+      liftIO (isShadowed wrapper) >>= \case
+        Nothing -> pure ()
+        Just pa -> lift $ logWarn $ T.pack $ prettyShow (ToolShadowed HLS pa wrapper ver)
+
+
+unsetHLS :: ( MonadMask m
+            , MonadReader env m
+            , HasDirs env
+            , MonadIO m)
+         => m ()
+unsetHLS = do
+  Dirs {..} <- getDirs
+  let wrapper = binDir </> "haskell-language-server-wrapper" <> exeExt
+  bins   <- liftIO $ handleIO (\_ -> pure []) $ findFiles'
+    binDir
+    (MP.chunk "haskell-language-server-" <* pvp' <* MP.chunk (T.pack exeExt) <* MP.eof)
+  forM_ bins (hideError doesNotExistErrorType . rmLink . (binDir </>))
+  hideError doesNotExistErrorType $ rmLink wrapper
+
+
+
+
+    ---------------
+    --[ Removal ]--
+    ---------------
+
+
+-- | Delete a hls version. Will try to fix the hls symlinks
+-- after removal (e.g. setting it to an older version).
+rmHLSVer :: ( MonadMask m
+            , MonadReader env m
+            , HasDirs env
+            , MonadThrow m
+            , HasLog env
+            , MonadIO m
+            , MonadFail m
+            , MonadCatch m
+            , MonadUnliftIO m
+            )
+         => Version
+         -> Excepts '[NotInstalled, UninstallFailed] m ()
+rmHLSVer ver = do
+  whenM (lift $ fmap not $ hlsInstalled ver) $ throwE (NotInstalled HLS (GHCTargetVersion Nothing ver))
+
+  isHlsSet <- lift hlsSet
+
+  liftE $ rmMinorHLSSymlinks ver
+
+  when (Just ver == isHlsSet) $ do
+    -- delete all set symlinks
+    liftE rmPlainHLS
+
+  hlsDir' <- ghcupHLSDir ver
+  let hlsDir = fromGHCupPath hlsDir'
+  lift (getInstalledFiles HLS (mkTVer ver)) >>= \case
+    Just files -> do
+      lift $ logInfo $ "Removing files safely from: " <> T.pack hlsDir
+      forM_ files (lift . hideError NoSuchThing . recycleFile . (\f -> hlsDir </> dropDrive f))
+      removeEmptyDirsRecursive hlsDir
+      survivors <- liftIO $ hideErrorDef [doesNotExistErrorType] [] $ listDirectory hlsDir
+      f <- recordedInstallationFile HLS (mkTVer ver)
+      lift $ recycleFile f
+      when (not (null survivors)) $ throwE $ UninstallFailed hlsDir survivors
+    Nothing -> do
+      isDir <- liftIO $ doesDirectoryExist hlsDir
+      isSyml <- liftIO $ handleIO (\_ -> pure False) $ pathIsSymbolicLink hlsDir
+      when (isDir && not isSyml) $ do
+        lift $ logInfo $ "Removing legacy directory recursively: " <> T.pack hlsDir
+        recyclePathForcibly hlsDir'
+
+  when (Just ver == isHlsSet) $ do
+    -- set latest hls
+    hlsVers <- lift $ fmap rights getInstalledHLSs
+    case headMay . reverse . sort $ hlsVers of
+      Just latestver -> liftE $ setHLS latestver SetHLSOnly Nothing
+      Nothing        -> pure ()
+
+
+getCabalVersion :: (MonadIO m, MonadFail m) => FilePath -> m Version
+getCabalVersion fp = do
+  contents <- liftIO $ B.readFile fp
+  gpd <- case parseGenericPackageDescriptionMaybe contents of
+           Nothing -> fail $ "could not parse cabal file: " <> fp
+           Just r -> pure r
+  let tver = (\c -> Version Nothing c [] Nothing)
+           . NE.fromList . fmap (NE.fromList . (:[]) . digits . fromIntegral)
+           . versionNumbers
+           . pkgVersion
+           . package
+           . packageDescription
+           $ gpd
+  pure tver
--- a/lib/GHCup/List.hs
+++ b/lib/GHCup/List.hs
@@ -0,0 +1,410 @@
+{-# LANGUAGE CPP                   #-}
+{-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
+
+{-|
+Module      : GHCup.List
+Description : Listing versions and tools
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+-}
+module GHCup.List where
+
+import           GHCup.Download
+import           GHCup.Errors
+import           GHCup.Types
+import           GHCup.Types.JSON               ( )
+import           GHCup.Types.Optics
+import           GHCup.Utils
+import           GHCup.Prelude.Logger
+import           GHCup.Version
+
+import           Control.Applicative
+import           Control.Exception.Safe
+import           Control.Monad
+#if !MIN_VERSION_base(4,13,0)
+import           Control.Monad.Fail             ( MonadFail )
+#endif
+import           Control.Monad.Reader
+import           Data.Either
+import           Data.List
+import           Data.Maybe
+import           Data.Text                      ( Text )
+import           Data.Versions                hiding ( patch )
+import           Haskus.Utils.Variant.Excepts
+import           Optics
+import           Prelude                 hiding ( abs
+                                                , writeFile
+                                                )
+
+import qualified Data.Map.Strict               as Map
+import qualified Data.Text                     as T
+
+
+
+
+
+
+
+
+
+
+    ------------------
+    --[ List tools ]--
+    ------------------
+
+
+-- | Filter data type for 'listVersions'.
+data ListCriteria = ListInstalled
+                  | ListSet
+                  | ListAvailable
+                  deriving Show
+
+-- | A list result describes a single tool version
+-- and various of its properties.
+data ListResult = ListResult
+  { lTool      :: Tool
+  , lVer       :: Version
+  , lCross     :: Maybe Text -- ^ currently only for GHC
+  , lTag       :: [Tag]
+  , lInstalled :: Bool
+  , lSet       :: Bool -- ^ currently active version
+  , fromSrc    :: Bool -- ^ compiled from source
+  , lStray     :: Bool -- ^ not in download info
+  , lNoBindist :: Bool -- ^ whether the version is available for this platform/arch
+  , hlsPowered :: Bool
+  }
+  deriving (Eq, Ord, Show)
+
+
+-- | Extract all available tool versions and their tags.
+availableToolVersions :: GHCupDownloads -> Tool -> Map.Map Version VersionInfo
+availableToolVersions av tool = view
+  (at tool % non Map.empty)
+  av
+
+
+-- | List all versions from the download info, as well as stray
+-- versions.
+listVersions :: ( MonadCatch m
+                , HasLog env
+                , MonadThrow m
+                , HasLog env
+                , MonadIO m
+                , MonadReader env m
+                , HasDirs env
+                , HasPlatformReq env
+                , HasGHCupInfo env
+                )
+             => Maybe Tool
+             -> Maybe ListCriteria
+             -> m [ListResult]
+listVersions lt' criteria = do
+  -- some annoying work to avoid too much repeated IO
+  cSet <- cabalSet
+  cabals <- getInstalledCabals
+  hlsSet' <- hlsSet
+  hlses <- getInstalledHLSs
+  sSet <- stackSet
+  stacks <- getInstalledStacks
+
+  go lt' cSet cabals hlsSet' hlses sSet stacks
+ where
+  go lt cSet cabals hlsSet' hlses sSet stacks = do
+    case lt of
+      Just t -> do
+        GHCupInfo { _ghcupDownloads = dls } <- getGHCupInfo
+        -- get versions from GHCupDownloads
+        let avTools = availableToolVersions dls t
+        lr <- filter' <$> forM (Map.toList avTools) (toListResult t cSet cabals hlsSet' hlses sSet stacks)
+
+        case t of
+          GHC -> do
+            slr <- strayGHCs avTools
+            pure (sort (slr ++ lr))
+          Cabal -> do
+            slr <- strayCabals avTools cSet cabals
+            pure (sort (slr ++ lr))
+          HLS -> do
+            slr <- strayHLS avTools hlsSet' hlses
+            pure (sort (slr ++ lr))
+          Stack -> do
+            slr <- strayStacks avTools sSet stacks
+            pure (sort (slr ++ lr))
+          GHCup -> do
+            let cg = maybeToList $ currentGHCup avTools
+            pure (sort (cg ++ lr))
+      Nothing -> do
+        ghcvers   <- go (Just GHC) cSet cabals hlsSet' hlses sSet stacks
+        cabalvers <- go (Just Cabal) cSet cabals hlsSet' hlses sSet stacks
+        hlsvers   <- go (Just HLS) cSet cabals hlsSet' hlses sSet stacks
+        ghcupvers <- go (Just GHCup) cSet cabals hlsSet' hlses sSet stacks
+        stackvers <- go (Just Stack) cSet cabals hlsSet' hlses sSet stacks
+        pure (ghcvers <> cabalvers <> hlsvers <> stackvers <> ghcupvers)
+  strayGHCs :: ( MonadCatch m
+               , MonadReader env m
+               , HasDirs env
+               , MonadThrow m
+               , HasLog env
+               , MonadIO m
+               )
+            => Map.Map Version VersionInfo
+            -> m [ListResult]
+  strayGHCs avTools = do
+    ghcs <- getInstalledGHCs
+    fmap catMaybes $ forM ghcs $ \case
+      Right tver@GHCTargetVersion{ _tvTarget = Nothing, .. } -> do
+        case Map.lookup _tvVersion avTools of
+          Just _  -> pure Nothing
+          Nothing -> do
+            lSet    <- fmap (maybe False (\(GHCTargetVersion _ v ) -> v == _tvVersion)) $ ghcSet Nothing
+            fromSrc <- ghcSrcInstalled tver
+            hlsPowered <- fmap (elem _tvVersion) hlsGHCVersions
+            pure $ Just $ ListResult
+              { lTool      = GHC
+              , lVer       = _tvVersion
+              , lCross     = Nothing
+              , lTag       = []
+              , lInstalled = True
+             , lStray     = isNothing (Map.lookup _tvVersion avTools)
+              , lNoBindist = False
+              , ..
+              }
+      Right tver@GHCTargetVersion{ .. } -> do
+        lSet    <- fmap (maybe False (\(GHCTargetVersion _ v ) -> v == _tvVersion)) $ ghcSet _tvTarget
+        fromSrc <- ghcSrcInstalled tver
+        hlsPowered <- fmap (elem _tvVersion) hlsGHCVersions
+        pure $ Just $ ListResult
+          { lTool      = GHC
+          , lVer       = _tvVersion
+          , lCross     = _tvTarget
+          , lTag       = []
+          , lInstalled = True
+          , lStray     = True -- NOTE: cross currently cannot be installed via bindist
+          , lNoBindist = False
+          , ..
+          }
+      Left e -> do
+        logWarn
+          $ "Could not parse version of stray directory" <> T.pack e
+        pure Nothing
+
+  strayCabals :: ( MonadReader env m
+                 , HasDirs env
+                 , MonadCatch m
+                 , MonadThrow m
+                 , HasLog env
+                 , MonadIO m
+                 )
+            => Map.Map Version VersionInfo
+            -> Maybe Version
+            -> [Either FilePath Version]
+            -> m [ListResult]
+  strayCabals avTools cSet cabals = do
+    fmap catMaybes $ forM cabals $ \case
+      Right ver ->
+        case Map.lookup ver avTools of
+          Just _  -> pure Nothing
+          Nothing -> do
+            let lSet = cSet == Just ver
+            pure $ Just $ ListResult
+              { lTool      = Cabal
+              , lVer       = ver
+              , lCross     = Nothing
+              , lTag       = []
+              , lInstalled = True
+              , lStray     = isNothing (Map.lookup ver avTools)
+              , lNoBindist = False
+              , fromSrc    = False -- actually, we don't know :>
+              , hlsPowered = False
+              , ..
+              }
+      Left e -> do
+        logWarn
+          $ "Could not parse version of stray directory" <> T.pack e
+        pure Nothing
+
+  strayHLS :: ( MonadReader env m
+              , HasDirs env
+              , MonadCatch m
+              , MonadThrow m
+              , HasLog env
+              , MonadIO m)
+           => Map.Map Version VersionInfo
+           -> Maybe Version
+           -> [Either FilePath Version]
+           -> m [ListResult]
+  strayHLS avTools hlsSet' hlss = do
+    fmap catMaybes $ forM hlss $ \case
+      Right ver ->
+        case Map.lookup ver avTools of
+          Just _  -> pure Nothing
+          Nothing -> do
+            let lSet = hlsSet' == Just ver
+            pure $ Just $ ListResult
+              { lTool      = HLS
+              , lVer       = ver
+              , lCross     = Nothing
+              , lTag       = []
+              , lInstalled = True
+              , lStray     = isNothing (Map.lookup ver avTools)
+              , lNoBindist = False
+              , fromSrc    = False -- actually, we don't know :>
+              , hlsPowered = False
+              , ..
+              }
+      Left e -> do
+        logWarn
+          $ "Could not parse version of stray directory" <> T.pack e
+        pure Nothing
+
+  strayStacks :: ( MonadReader env m
+                 , HasDirs env
+                 , MonadCatch m
+                 , MonadThrow m
+                 , HasLog env
+                 , MonadIO m
+                 )
+              => Map.Map Version VersionInfo
+              -> Maybe Version
+              -> [Either FilePath Version]
+              -> m [ListResult]
+  strayStacks avTools stackSet' stacks = do
+    fmap catMaybes $ forM stacks $ \case
+      Right ver ->
+        case Map.lookup ver avTools of
+          Just _  -> pure Nothing
+          Nothing -> do
+            let lSet = stackSet' == Just ver
+            pure $ Just $ ListResult
+              { lTool      = Stack
+              , lVer       = ver
+              , lCross     = Nothing
+              , lTag       = []
+              , lInstalled = True
+              , lStray     = isNothing (Map.lookup ver avTools)
+              , lNoBindist = False
+              , fromSrc    = False -- actually, we don't know :>
+              , hlsPowered = False
+              , ..
+              }
+      Left e -> do
+        logWarn
+          $ "Could not parse version of stray directory" <> T.pack e
+        pure Nothing
+
+  currentGHCup :: Map.Map Version VersionInfo -> Maybe ListResult
+  currentGHCup av =
+    let currentVer = fromJust $ pvpToVersion ghcUpVer ""
+        listVer    = Map.lookup currentVer av
+        latestVer  = fst <$> headOf (getTagged Latest) av
+        recommendedVer = fst <$> headOf (getTagged Latest) av
+        isOld  = maybe True (> currentVer) latestVer && maybe True (> currentVer) recommendedVer
+    in if | Map.member currentVer av -> Nothing
+          | otherwise -> Just $ ListResult { lVer    = currentVer
+                                           , lTag    = maybe (if isOld then [Old] else []) _viTags listVer
+                                           , lCross  = Nothing
+                                           , lTool   = GHCup
+                                           , fromSrc = False
+                                           , lStray  = isNothing listVer
+                                           , lSet    = True
+                                           , lInstalled = True
+                                           , lNoBindist = False
+                                           , hlsPowered = False
+                                           }
+
+  -- NOTE: this are not cross ones, because no bindists
+  toListResult :: ( HasLog env
+                  , MonadReader env m
+                  , HasDirs env
+                  , HasGHCupInfo env
+                  , HasPlatformReq env
+                  , MonadIO m
+                  , MonadCatch m
+                  )
+               => Tool
+               -> Maybe Version
+               -> [Either FilePath Version]
+               -> Maybe Version
+               -> [Either FilePath Version]
+               -> Maybe Version
+               -> [Either FilePath Version]
+               -> (Version, VersionInfo)
+               -> m ListResult
+  toListResult t cSet cabals hlsSet' hlses stackSet' stacks (v, _viTags -> tags) = do
+    case t of
+      GHC -> do
+        lNoBindist <- fmap (isLeft . veitherToEither) $ runE @'[NoDownload] $ getDownloadInfo GHC v
+        let tver = mkTVer v
+        lSet       <- fmap (maybe False (\(GHCTargetVersion _ v') -> v' == v)) $ ghcSet Nothing
+        lInstalled <- ghcInstalled tver
+        fromSrc    <- ghcSrcInstalled tver
+        hlsPowered <- fmap (elem v) hlsGHCVersions
+        pure ListResult { lVer = v, lCross = Nothing , lTag = tags, lTool = t, lStray = False, .. }
+      Cabal -> do
+        lNoBindist <- fmap (isLeft . veitherToEither) $ runE @'[NoDownload] $ getDownloadInfo Cabal v
+        let lSet = cSet == Just v
+        let lInstalled = elem v $ rights cabals
+        pure ListResult { lVer    = v
+                        , lCross  = Nothing
+                        , lTag    = tags
+                        , lTool   = t
+                        , fromSrc = False
+                        , lStray  = False
+                        , hlsPowered = False
+                        , ..
+                        }
+      GHCup -> do
+        let lSet       = prettyPVP ghcUpVer == prettyVer v
+        let lInstalled = lSet
+        pure ListResult { lVer    = v
+                        , lTag    = tags
+                        , lCross  = Nothing
+                        , lTool   = t
+                        , fromSrc = False
+                        , lStray  = False
+                        , lNoBindist = False
+                        , hlsPowered = False
+                        , ..
+                        }
+      HLS -> do
+        lNoBindist <- fmap (isLeft . veitherToEither) $ runE @'[NoDownload] $ getDownloadInfo HLS v
+        let lSet = hlsSet' == Just v
+        let lInstalled = elem v $ rights hlses
+        pure ListResult { lVer    = v
+                        , lCross  = Nothing
+                        , lTag    = tags
+                        , lTool   = t
+                        , fromSrc = False
+                        , lStray  = False
+                        , hlsPowered = False
+                        , ..
+                        }
+      Stack -> do
+        lNoBindist <- fmap (isLeft . veitherToEither) $ runE @'[NoDownload] $ getDownloadInfo Stack v
+        let lSet = stackSet' == Just v
+        let lInstalled = elem v $ rights stacks
+        pure ListResult { lVer    = v
+                        , lCross  = Nothing
+                        , lTag    = tags
+                        , lTool   = t
+                        , fromSrc = False
+                        , lStray  = False
+                        , hlsPowered = False
+                        , ..
+                        }
+
+
+  filter' :: [ListResult] -> [ListResult]
+  filter' lr = case criteria of
+    Nothing            -> lr
+    Just ListInstalled -> filter (\ListResult {..} -> lInstalled) lr
+    Just ListSet       -> filter (\ListResult {..} -> lSet) lr
+    Just ListAvailable -> filter (\ListResult {..} -> not lNoBindist) lr
+
--- a/lib/GHCup/Platform.hs
+++ b/lib/GHCup/Platform.hs
@@ -23,10 +23,11 @@ import           GHCup.Errors
 import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Types.JSON               ( )
-import           GHCup.Utils.File
-import           GHCup.Utils.Logger
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.String.QQ
+import           GHCup.Utils.Dirs
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
+import           GHCup.Prelude.Process
+import           GHCup.Prelude.String.QQ

 #if !MIN_VERSION_base(4,13,0)
 import           Control.Monad.Fail             ( MonadFail )
@@ -46,7 +47,6 @@ import           Prelude                 hiding ( abs
                                                , writeFile
                                                )
 import           System.Info
-import           System.Directory
 import           System.OsRelease
 import           Text.PrettyPrint.HughesPJClass ( prettyShow )
 import           Text.Regex.Posix
--- a/lib/GHCup/Prelude.hs
+++ b/lib/GHCup/Prelude.hs
@@ -0,0 +1,82 @@
+{-# LANGUAGE CPP                 #-}
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE FlexibleInstances   #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
+
+{-|
+Module      : GHCup.Prelude
+Description : MegaParsec utilities
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+
+GHCup specific prelude. Lots of Excepts functionality.
+-}
+module GHCup.Prelude
+  (module GHCup.Prelude,
+   module GHCup.Prelude.Internal,
+#if defined(IS_WINDOWS)
+   module GHCup.Prelude.Windows
+#else
+   module GHCup.Prelude.Posix
+#endif
+  )
+where
+
+import           GHCup.Errors
+import           GHCup.Prelude.Internal
+import           GHCup.Types.Optics   (HasLog)
+import           GHCup.Prelude.Logger (logWarn)
+#if defined(IS_WINDOWS)
+import GHCup.Prelude.Windows
+#else
+import GHCup.Prelude.Posix
+#endif
+
+import           Control.Monad.IO.Class
+import           Control.Monad.Reader
+import           Haskus.Utils.Variant.Excepts
+import           Text.PrettyPrint.HughesPJClass ( prettyShow, Pretty )
+import qualified Data.Text                     as T
+
+
+
+-- for some obscure reason... this won't type-check if we move it to a different module
+catchWarn :: forall es m env . ( Pretty (V es)
+                             , MonadReader env m
+                             , HasLog env
+                             , MonadIO m
+                             , Monad m) => Excepts es m () -> Excepts '[] m ()
+catchWarn = catchAllE @_ @es (\v -> lift $ logWarn (T.pack . prettyShow $ v))
+
+
+runBothE' :: forall e m a b .
+             ( Monad m
+             , Show (V e)
+             , Pretty (V e)
+             , PopVariant InstallSetError e
+             , LiftVariant' e (InstallSetError ': e)
+             , e :<< (InstallSetError ': e)
+             )
+          => Excepts e m a
+          -> Excepts e m b
+          -> Excepts (InstallSetError ': e) m ()
+runBothE' a1 a2 = do
+   r1 <- lift $ runE @e a1
+   r2 <- lift $ runE @e a2
+   case (r1, r2) of
+      (VLeft e1, VLeft e2) -> throwE (InstallSetError e1 e2)
+      (VLeft e , _       ) -> throwSomeE e
+      (_       , VLeft e ) -> throwSomeE e
+      (VRight _, VRight _) -> pure ()
+
+
+-- | Throw some exception
+throwSomeE :: forall es' es a m. (Monad m, LiftVariant es' es) => V es' -> Excepts es m a
+{-# INLINABLE throwSomeE #-}
+throwSomeE = Excepts . pure . VLeft . liftVariant
--- a/lib/GHCup/Prelude/File.hs
+++ b/lib/GHCup/Prelude/File.hs
@@ -0,0 +1,426 @@
+{-# LANGUAGE CPP                 #-}
+{-# LANGUAGE BangPatterns        #-}
+{-# LANGUAGE DataKinds           #-}
+{-# LANGUAGE FlexibleContexts    #-}
+{-# LANGUAGE FlexibleInstances   #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE OverloadedStrings   #-}
+{-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
+
+module GHCup.Prelude.File (
+  mergeFileTree,
+  copyFileE,
+  findFilesDeep,
+  getDirectoryContentsRecursive,
+  getDirectoryContentsRecursiveBFS,
+  getDirectoryContentsRecursiveDFS,
+  getDirectoryContentsRecursiveUnsafe,
+  getDirectoryContentsRecursiveBFSUnsafe,
+  getDirectoryContentsRecursiveDFSUnsafe,
+  recordedInstallationFile,
+  module GHCup.Prelude.File.Search,
+
+  chmod_755,
+  isBrokenSymlink,
+  copyFile,
+  deleteFile,
+  install,
+  removeEmptyDirectory,
+  removeDirIfEmptyOrIsSymlink,
+  removeEmptyDirsRecursive,
+  rmFileForce,
+  createDirRecursive',
+  recyclePathForcibly,
+  rmDirectory,
+  recycleFile,
+  rmFile,
+  rmDirectoryLink,
+  moveFilePortable,
+  moveFile,
+  rmPathForcibly,
+
+  exeExt,
+  exeExt',
+  getLinkTarget,
+  pathIsLink,
+  rmLink,
+  createLink
+) where
+
+import GHCup.Utils.Dirs
+import GHCup.Prelude.Logger.Internal (logInfo, logDebug)
+import GHCup.Prelude.Internal
+import GHCup.Prelude.File.Search
+#if IS_WINDOWS
+import GHCup.Prelude.File.Windows
+import GHCup.Prelude.Windows
+#else
+import GHCup.Prelude.File.Posix
+import GHCup.Prelude.Posix
+#endif
+import           GHCup.Errors
+import           GHCup.Types
+import           GHCup.Types.Optics
+
+import           Text.Regex.Posix
+import           Control.Monad.IO.Unlift        ( MonadUnliftIO )
+import           Control.Exception.Safe
+import           Control.Monad.Reader
+import           Data.ByteString                ( ByteString )
+import           Haskus.Utils.Variant.Excepts
+import           System.FilePath
+import           Text.PrettyPrint.HughesPJClass (prettyShow)
+
+import qualified Data.Text                     as T
+import qualified Streamly.Prelude              as S
+import Control.DeepSeq (force)
+import Control.Exception (evaluate)
+import GHC.IO.Exception
+import System.IO.Error
+
+
+-- | Merge one file tree to another given a copy operation.
+--
+-- Records every successfully installed file into the destination
+-- returned by 'recordedInstallationFile'.
+--
+-- If any copy operation fails, the record file is deleted, as well
+-- as the partially installed files.
+mergeFileTree :: ( MonadMask m
+                 , S.MonadAsync m
+                 , MonadReader env m
+                 , HasDirs env
+                 , HasLog env
+                 , MonadCatch m
+                 )
+              => GHCupPath                       -- ^ source base directory from which to install findFiles
+              -> InstallDirResolved              -- ^ destination base dir
+              -> Tool
+              -> GHCTargetVersion
+              -> (FilePath -> FilePath -> m ())  -- ^ file copy operation
+              -> Excepts '[MergeFileTreeError] m ()
+mergeFileTree _ (GHCupBinDir fp) _ _ _ =
+  throwIO $ userError ("mergeFileTree: internal error, called on " <> fp)
+mergeFileTree sourceBase destBase tool v' copyOp = do
+  lift $ logInfo $ "Merging file tree from \""
+       <> T.pack (fromGHCupPath sourceBase)
+       <> "\" to \""
+       <> T.pack (fromInstallDir destBase)
+       <> "\""
+  recFile <- recordedInstallationFile tool v'
+
+  wrapInExcepts $ do
+    -- These checks are not atomic, but we perform them to have
+    -- the opportunity to abort before copying has started.
+    --
+    -- The actual copying might still fail.
+    liftIO $ baseCheck (fromGHCupPath sourceBase)
+    liftIO $ destCheck (fromInstallDir destBase)
+
+    -- we only record for non-isolated installs
+    when (isSafeDir destBase) $ do
+      whenM (liftIO $ doesFileExist recFile)
+        $ throwIO $ userError ("mergeFileTree: DB file " <> recFile <> " already exists!")
+      liftIO $ createDirectoryIfMissing True (takeDirectory recFile)
+
+  -- we want the cleanup action to leak through in case of exception
+  onE_ (cleanupOnPartialInstall recFile) $ wrapInExcepts $ do
+    logDebug "Starting merge"
+    lift $ flip S.mapM_ (getDirectoryContentsRecursive sourceBase) $ \f -> do
+      copy f
+      logDebug $ T.pack "Recording installed file: " <> T.pack f
+      recordInstalledFile f recFile
+      pure f
+
+ where
+  wrapInExcepts = handleIO (\e -> throwE $ MergeFileTreeError e (fromGHCupPath sourceBase) (fromInstallDir destBase))
+
+  cleanupOnPartialInstall recFile = when (isSafeDir destBase) $ do
+    (force -> !l) <- hideErrorDef [NoSuchThing] [] $ lines <$> liftIO
+      (readFile recFile >>= evaluate)
+    logDebug "Deleting recorded files due to partial install"
+    forM_ l $ \f -> do
+      let dest = fromInstallDir destBase </> dropDrive f
+      logDebug $ "rm -f " <> T.pack f
+      hideError NoSuchThing $ rmFile dest
+      pure ()
+    logDebug $ "rm -f " <> T.pack recFile
+    hideError NoSuchThing $ rmFile recFile
+    logDebug $ "rm -f " <> T.pack (fromInstallDir destBase)
+    hideError UnsatisfiedConstraints $ hideError NoSuchThing $
+      removeEmptyDirsRecursive (fromInstallDir destBase)
+
+
+  recordInstalledFile f recFile = when (isSafeDir destBase) $
+    liftIO $ appendFile recFile (f <> "\n")
+
+  copy source = do
+    let dest = fromInstallDir destBase </> source
+        src  = fromGHCupPath sourceBase </> source
+
+    when (isAbsolute source)
+      $ throwIO $ userError ("mergeFileTree: source file " <> source <> " is not relative!")
+
+    liftIO . createDirectoryIfMissing True . takeDirectory $ dest
+
+    copyOp src dest
+
+
+  baseCheck src = do
+      when (isRelative src)
+        $ throwIO $ userError ("mergeFileTree: source base directory " <> src <> " is not absolute!")
+      whenM (not <$> doesDirectoryExist src)
+        $ throwIO $ userError ("mergeFileTree: source base directory " <> src <> " does not exist!")
+  destCheck dest = do
+      when (isRelative dest)
+        $ throwIO $ userError ("mergeFileTree: destination base directory " <> dest <> " is not absolute!")
+
+
+
+copyFileE :: (CopyError :< xs, MonadCatch m, MonadIO m) => FilePath -> FilePath -> Bool -> Excepts xs m ()
+copyFileE from to = handleIO (throwE . CopyError . show) . liftIO . copyFile from to
+
+
+-- | List all the files in a directory and all subdirectories.
+--
+-- The order places files in sub-directories after all the files in their
+-- parent directories. The list is generated lazily so is not well defined if
+-- the source directory structure changes before the list is used.
+--
+-- depth first
+getDirectoryContentsRecursiveDFS :: (MonadCatch m, S.MonadAsync m, MonadMask m)
+                                 => GHCupPath
+                                 -> S.SerialT m FilePath
+getDirectoryContentsRecursiveDFS (fromGHCupPath -> fp) = getDirectoryContentsRecursiveDFSUnsafe fp
+
+-- breadth first
+getDirectoryContentsRecursiveBFS :: (MonadCatch m, S.MonadAsync m, MonadMask m)
+                                 => GHCupPath
+                                 -> S.SerialT m FilePath
+getDirectoryContentsRecursiveBFS (fromGHCupPath -> fp) = getDirectoryContentsRecursiveBFSUnsafe fp
+
+
+getDirectoryContentsRecursive :: (MonadCatch m, S.MonadAsync m, MonadMask m)
+                              => GHCupPath
+                              -> S.SerialT m FilePath
+getDirectoryContentsRecursive = getDirectoryContentsRecursiveBFS
+
+getDirectoryContentsRecursiveUnsafe :: (MonadCatch m, S.MonadAsync m, MonadMask m)
+                                    => FilePath
+                                    -> S.SerialT m FilePath
+getDirectoryContentsRecursiveUnsafe = getDirectoryContentsRecursiveBFSUnsafe
+
+findFilesDeep :: GHCupPath -> Regex -> IO [FilePath]
+findFilesDeep path regex =
+  S.toList $ S.filter (match regex) $ getDirectoryContentsRecursive path
+
+
+recordedInstallationFile :: ( MonadReader env m
+                            , HasDirs env
+                            )
+                         => Tool
+                         -> GHCTargetVersion
+                         -> m FilePath
+recordedInstallationFile t v' = do
+  Dirs {..}  <- getDirs
+  pure (fromGHCupPath dbDir </> prettyShow t </> T.unpack (tVerToText v'))
+
+removeDirIfEmptyOrIsSymlink :: (MonadMask m, MonadIO m, MonadCatch m) => FilePath -> m ()
+removeDirIfEmptyOrIsSymlink filepath =
+  hideError UnsatisfiedConstraints $
+  handleIO' InappropriateType
+        (handleIfSym filepath)
+        (liftIO $ removeEmptyDirectory filepath)
+  where
+    handleIfSym fp e = do
+      isSym <- liftIO $ pathIsSymbolicLink fp
+      if isSym
+      then rmFileForce fp
+      else liftIO $ ioError e
+
+removeEmptyDirsRecursive :: (MonadMask m, MonadIO m, MonadCatch m) => FilePath -> m ()
+removeEmptyDirsRecursive = go
+ where
+  go fp = do
+    cs <- liftIO $ listDirectory fp >>= filterM doesDirectoryExist . fmap (fp </>)
+    forM_ cs go
+    liftIO $ removeEmptyDirectory fp
+
+rmFileForce :: (MonadMask m, MonadIO m) => FilePath -> m ()
+rmFileForce filepath = do
+  hideError doesNotExistErrorType
+    $ hideError InappropriateType $ rmFile filepath
+
+-- | More permissive version of 'createDirRecursive'. This doesn't
+-- error when the destination is a symlink to a directory.
+createDirRecursive' :: FilePath -> IO ()
+createDirRecursive' p =
+  handleIO (\e -> if isAlreadyExistsError e then isSymlinkDir e else throwIO e)
+    . createDirectoryIfMissing True
+    $ p
+
+ where
+  isSymlinkDir e = do
+    ft <- pathIsSymbolicLink p
+    case ft of
+      True -> do
+        rp <- canonicalizePath p
+        rft <- doesDirectoryExist rp
+        case rft of
+          True -> pure ()
+          _ -> throwIO e
+      _ -> throwIO e
+
+
+-- https://github.com/haskell/directory/issues/110
+-- https://github.com/haskell/directory/issues/96
+-- https://www.sqlite.org/src/info/89f1848d7f
+recyclePathForcibly :: ( MonadIO m
+                       , MonadReader env m
+                       , HasDirs env
+                       , MonadMask m
+                       )
+                    => GHCupPath
+                    -> m ()
+recyclePathForcibly fp
+  | isWindows = do
+      Dirs { recycleDir } <- getDirs
+      tmp <- liftIO $ createTempGHCupDirectory recycleDir "recyclePathForcibly"
+      let dest = tmp `appendGHCupPath` takeFileName (fromGHCupPath fp)
+      liftIO (moveFile (fromGHCupPath fp) (fromGHCupPath dest))
+          `catch`
+          (\e -> if | isDoesNotExistError e -> pure ()
+                    | isPermissionError e || ioeGetErrorType e == UnsupportedOperation {- EXDEV on windows -} -> recover (liftIO $ removePathForcibly fp)
+                    | otherwise -> throwIO e)
+          `finally`
+            liftIO (handleIO (\_ -> pure ()) $ removePathForcibly tmp)
+  | otherwise = liftIO $ removePathForcibly fp
+
+
+
+rmDirectory :: (MonadIO m, MonadMask m)
+            => GHCupPath
+            -> m ()
+rmDirectory fp
+  | isWindows = recover (liftIO $ removeDirectory fp)
+  | otherwise = liftIO $ removeDirectory fp
+
+
+-- https://www.sqlite.org/src/info/89f1848d7f
+-- https://github.com/haskell/directory/issues/96
+recycleFile :: ( MonadIO m
+               , MonadMask m
+               , MonadReader env m
+               , HasDirs env
+               )
+            => FilePath
+            -> m ()
+recycleFile fp
+  | isWindows = do
+      Dirs { recycleDir } <- getDirs
+      liftIO $ whenM (doesDirectoryExist fp) $ ioError (IOError Nothing InappropriateType "recycleFile" "" Nothing (Just fp))
+      tmp <- liftIO $ createTempGHCupDirectory recycleDir "recycleFile"
+      let dest = fromGHCupPath tmp </> takeFileName fp
+      liftIO (moveFile fp dest)
+        `catch`
+          (\e -> if isPermissionError e || ioeGetErrorType e == UnsupportedOperation {- EXDEV on windows -} then recover (liftIO $ rmFile fp) else throwIO e)
+        `finally`
+          liftIO (handleIO (\_ -> pure ()) $ removePathForcibly tmp)
+  | otherwise = liftIO $ removeFile fp
+
+
+rmFile :: ( MonadIO m
+          , MonadMask m
+          )
+      => FilePath
+      -> m ()
+rmFile fp
+  | isWindows = recover (liftIO $ removeFile fp)
+  | otherwise = liftIO $ removeFile fp
+
+
+rmDirectoryLink :: (MonadIO m, MonadMask m, MonadReader env m, HasDirs env)
+                => FilePath
+                -> m ()
+rmDirectoryLink fp
+  | isWindows = recover (liftIO $ removeDirectoryLink fp)
+  | otherwise = liftIO $ removeDirectoryLink fp
+
+
+rmPathForcibly :: ( MonadIO m
+                  , MonadMask m
+                  )
+               => GHCupPath
+               -> m ()
+rmPathForcibly fp
+  | isWindows = recover (liftIO $ removePathForcibly fp)
+  | otherwise = liftIO $ removePathForcibly fp
+
+
+-- | The file extension for executables.
+exeExt :: String
+exeExt
+  | isWindows = ".exe"
+  | otherwise = ""
+
+-- | The file extension for executables.
+exeExt' :: ByteString
+exeExt'
+  | isWindows = ".exe"
+  | otherwise = ""
+
+
+rmLink :: (MonadReader env m, HasDirs env, MonadIO m, MonadMask m) => FilePath -> m ()
+rmLink fp
+  | isWindows = do
+      hideError doesNotExistErrorType . recycleFile $ fp
+      hideError doesNotExistErrorType . recycleFile $ (dropExtension fp <.> "shim")
+  | otherwise = hideError doesNotExistErrorType . recycleFile $ fp
+
+
+-- | Creates a symbolic link on unix and a fake symlink on windows for
+-- executables, which:
+--     1. is a shim exe
+--     2. has a corresponding .shim file in the same directory that
+--        contains the target
+--
+-- This overwrites previously existing files.
+--
+-- On windows, this requires that 'ensureGlobalTools' was run beforehand.
+createLink :: ( MonadMask m
+              , MonadThrow m
+              , HasLog env
+              , MonadIO m
+              , MonadReader env m
+              , HasDirs env
+              , MonadUnliftIO m
+              , MonadFail m
+              )
+           => FilePath      -- ^ path to the target executable
+           -> FilePath      -- ^ path to be created
+           -> m ()
+createLink link exe
+  | isWindows = do
+      dirs <- getDirs
+      let shimGen = fromGHCupPath (cacheDir dirs) </> "gs.exe"
+
+      let shim = dropExtension exe <.> "shim"
+          -- For hardlinks, link needs to be absolute.
+          -- If link is relative, it's relative to the target exe.
+          -- Note that (</>) drops lhs when rhs is absolute.
+          fullLink = takeDirectory exe </> link
+          shimContents = "path = " <> fullLink
+
+      logDebug $ "rm -f " <> T.pack exe
+      rmLink exe
+
+      logDebug $ "ln -s " <> T.pack fullLink <> " " <> T.pack exe
+      liftIO $ copyFile shimGen exe False
+      liftIO $ writeFile shim shimContents
+  | otherwise = do
+      logDebug $ "rm -f " <> T.pack exe
+      hideError doesNotExistErrorType $ recycleFile exe
+
+      logDebug $ "ln -s " <> T.pack link <> " " <> T.pack exe
+      liftIO $ createFileLink link exe
--- a/lib/GHCup/Prelude/File/Posix.hs
+++ b/lib/GHCup/Prelude/File/Posix.hs
@@ -0,0 +1,324 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE DataKinds  #-}
+{-# LANGUAGE MultiWayIf  #-}
+{-# LANGUAGE CApiFFI #-}
+
+{-|
+Module      : GHCup.Utils.File.Posix
+Description : File and directory handling for unix
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : POSIX
+-}
+module GHCup.Prelude.File.Posix where
+
+import           GHCup.Prelude.File.Posix.Traversals
+
+import           Control.Exception.Safe
+import           Control.Monad.Reader
+import           Foreign.C.String
+import           Foreign.C.Error
+import           Foreign.C.Types
+import           System.IO                      ( hClose, hSetBinaryMode )
+import           System.IO.Error      hiding    ( catchIOError )
+import           System.FilePath
+import           System.Directory               ( removeFile, pathIsSymbolicLink, getSymbolicLinkTarget, doesPathExist )
+import           System.Posix.Directory
+import           System.Posix.Error             ( throwErrnoPathIfMinus1Retry )
+import           System.Posix.Internals         ( withFilePath )
+import           System.Posix.Files
+import           System.Posix.Types
+
+
+import qualified System.Posix.Directory        as PD
+import qualified System.Posix.Files            as PF
+import qualified System.Posix.IO               as SPI
+import qualified System.Posix as Posix
+import qualified Streamly.FileSystem.Handle    as FH
+import qualified Streamly.Internal.FileSystem.Handle
+                                               as IFH
+import qualified Streamly.Prelude              as S
+import qualified GHCup.Prelude.File.Posix.Foreign as FD
+import qualified Streamly.Internal.Data.Stream.StreamD.Type
+                                               as D
+import           Streamly.Internal.Data.Unfold.Type
+import qualified Streamly.Internal.Data.Unfold as U
+import           Streamly.Internal.Control.Concurrent ( withRunInIO )
+import           Streamly.Internal.Data.IOFinalizer   ( newIOFinalizer, runIOFinalizer )
+
+
+-- | On unix, we can use symlinks, so we just get the
+-- symbolic link target.
+--
+-- On windows, we have to emulate symlinks via shims,
+-- see 'createLink'.
+getLinkTarget :: FilePath -> IO FilePath
+getLinkTarget = getSymbolicLinkTarget
+
+
+-- | Checks whether the path is a link.
+pathIsLink :: FilePath -> IO Bool
+pathIsLink = pathIsSymbolicLink
+
+
+chmod_755 :: MonadIO m => FilePath -> m ()
+chmod_755 fp = do
+  let exe_mode =
+          nullFileMode
+            `unionFileModes` ownerExecuteMode
+            `unionFileModes` ownerReadMode
+            `unionFileModes` ownerWriteMode
+            `unionFileModes` groupExecuteMode
+            `unionFileModes` groupReadMode
+            `unionFileModes` otherExecuteMode
+            `unionFileModes` otherReadMode
+  liftIO $ setFileMode fp exe_mode
+
+
+-- |Default permissions for a new file.
+newFilePerms :: FileMode
+newFilePerms =
+  ownerWriteMode
+    `unionFileModes` ownerReadMode
+    `unionFileModes` groupWriteMode
+    `unionFileModes` groupReadMode
+    `unionFileModes` otherWriteMode
+    `unionFileModes` otherReadMode
+
+
+-- | Checks whether the binary is a broken link.
+isBrokenSymlink :: FilePath -> IO Bool
+isBrokenSymlink fp = do
+  try (pathIsSymbolicLink fp) >>= \case
+    Right True -> do
+      let symDir = takeDirectory fp
+      tfp <- getSymbolicLinkTarget fp
+      not <$> doesPathExist
+        -- this drops 'symDir' if 'tfp' is absolute
+        (symDir </> tfp)
+    Right b -> pure b
+    Left e | isDoesNotExistError e -> pure False
+           | otherwise -> throwIO e
+
+copyFile :: FilePath   -- ^ source file
+         -> FilePath   -- ^ destination file
+         -> Bool       -- ^ fail if file exists
+         -> IO ()
+copyFile from to fail' = do
+  bracket
+    (openFdHandle from SPI.ReadOnly [FD.oNofollow] Nothing)
+    (hClose . snd)
+    $ \(fromFd, fH) -> do
+        sourceFileMode <- fileMode <$> getFdStatus fromFd
+        let dflags = [ FD.oNofollow
+                     , if fail' then FD.oExcl else FD.oTrunc
+                     ]
+        bracket
+          (openFdHandle to SPI.WriteOnly dflags $ Just sourceFileMode)
+          (hClose . snd)
+          $ \(_, tH) -> do
+              hSetBinaryMode fH True
+              hSetBinaryMode tH True
+              streamlyCopy (fH, tH)
+ where
+  openFdHandle fp omode flags fM = do
+    fd      <- openFd' fp omode flags fM
+    handle' <- SPI.fdToHandle fd
+    pure (fd, handle')
+  streamlyCopy (fH, tH) =
+    S.fold (FH.writeChunks tH) $ IFH.toChunksWithBufferOf (256 * 1024) fH
+
+foreign import capi unsafe "fcntl.h open"
+   c_open :: CString -> CInt -> Posix.CMode -> IO CInt
+
+
+open_  :: CString
+       -> Posix.OpenMode
+       -> [FD.Flags]
+       -> Maybe Posix.FileMode
+       -> IO Posix.Fd
+open_ str how optional_flags maybe_mode = do
+    fd <- c_open str all_flags mode_w
+    return (Posix.Fd fd)
+  where
+    all_flags  = FD.unionFlags $ optional_flags ++ [open_mode] ++ creat
+
+
+    (creat, mode_w) = case maybe_mode of
+                        Nothing -> ([],0)
+                        Just x  -> ([FD.oCreat], x)
+
+    open_mode = case how of
+                   Posix.ReadOnly  -> FD.oRdonly
+                   Posix.WriteOnly -> FD.oWronly
+                   Posix.ReadWrite -> FD.oRdwr
+
+
+-- |Open and optionally create this file. See 'System.Posix.Files'
+-- for information on how to use the 'FileMode' type.
+--
+-- Note that passing @Just x@ as the 4th argument triggers the
+-- `oCreat` status flag, which must be set when you pass in `oExcl`
+-- to the status flags. Also see the manpage for @open(2)@.
+openFd' :: FilePath
+        -> Posix.OpenMode
+        -> [FD.Flags]               -- ^ status flags of @open(2)@
+        -> Maybe Posix.FileMode  -- ^ @Just x@ => creates the file with the given modes, Nothing => the file must exist.
+        -> IO Posix.Fd
+openFd' name how optional_flags maybe_mode =
+   withFilePath name $ \str ->
+     throwErrnoPathIfMinus1Retry "openFd" name $
+       open_ str how optional_flags maybe_mode
+
+
+-- |Deletes the given file. Raises `eISDIR`
+-- if run on a directory. Does not follow symbolic links.
+--
+-- Throws:
+--
+--    - `InappropriateType` for wrong file type (directory)
+--    - `NoSuchThing` if the file does not exist
+--    - `PermissionDenied` if the directory cannot be read
+--
+-- Notes: calls `unlink`
+deleteFile :: FilePath -> IO ()
+deleteFile = removeLink
+
+
+-- |Recreate a symlink.
+--
+-- In `Overwrite` copy mode only files and empty directories are deleted.
+--
+-- Safety/reliability concerns:
+--
+--    * `Overwrite` mode is inherently non-atomic
+--
+-- Throws:
+--
+--    - `InvalidArgument` if source file is wrong type (not a symlink)
+--    - `PermissionDenied` if output directory cannot be written to
+--    - `PermissionDenied` if source directory cannot be opened
+--    - `SameFile` if source and destination are the same file
+--      (`HPathIOException`)
+--
+--
+-- Throws in `Strict` mode only:
+--
+--    - `AlreadyExists` if destination already exists
+--
+-- Throws in `Overwrite` mode only:
+--
+--    - `UnsatisfiedConstraints` if destination file is non-empty directory
+--
+-- Notes:
+--
+--    - calls `symlink`
+recreateSymlink :: FilePath   -- ^ the old symlink file
+                -> FilePath   -- ^ destination file
+                -> Bool       -- ^ fail if destination file exists
+                -> IO ()
+recreateSymlink symsource newsym fail' = do
+  sympoint <- readSymbolicLink symsource
+  case fail' of
+    True  -> pure ()
+    False ->
+      handleIO (\e -> if doesNotExistErrorType  == ioeGetErrorType e then pure () else liftIO . ioError $ e) $ deleteFile newsym
+  createSymbolicLink sympoint newsym
+
+
+-- copys files, recreates symlinks, fails on all other types
+install :: FilePath -> FilePath -> Bool -> IO ()
+install from to fail' = do
+  fs <- PF.getSymbolicLinkStatus from
+  decide fs
+ where
+  decide fs | PF.isRegularFile fs     = copyFile from to fail'
+            | PF.isSymbolicLink fs    = recreateSymlink from to fail'
+            | otherwise               = ioError $ mkIOError illegalOperationErrorType "install: not a regular file or symlink" Nothing (Just from)
+
+moveFile :: FilePath -> FilePath -> IO ()
+moveFile = rename
+
+
+moveFilePortable :: FilePath -> FilePath -> IO ()
+moveFilePortable from to = do
+  catchErrno [eXDEV] (moveFile from to) $ do
+    copyFile from to True
+    removeFile from
+
+
+catchErrno :: [Errno] -- ^ errno to catch
+           -> IO a    -- ^ action to try, which can raise an IOException
+           -> IO a    -- ^ action to carry out in case of an IOException and
+                      --   if errno matches
+           -> IO a
+catchErrno en a1 a2 =
+  catchIOError a1 $ \e -> do
+    errno <- getErrno
+    if errno `elem` en
+      then a2
+      else ioError e
+
+removeEmptyDirectory :: FilePath -> IO ()
+removeEmptyDirectory = PD.removeDirectory
+
+
+-- | Create an 'Unfold' of directory contents.
+unfoldDirContents :: (MonadMask m, MonadIO m, S.MonadAsync m) => Unfold m FilePath (FD.DirType, FilePath)
+unfoldDirContents = U.bracket (liftIO . openDirStream) (liftIO . closeDirStream) (Unfold step return)
+ where
+  {-# INLINE [0] step #-}
+  step dirstream = do
+    (typ, e) <- liftIO $ readDirEnt dirstream
+    return $ if
+      | null e    -> D.Stop
+      | "." == e  -> D.Skip dirstream
+      | ".." == e -> D.Skip dirstream
+      | otherwise -> D.Yield (typ, e) dirstream
+
+
+getDirectoryContentsRecursiveDFSUnsafe :: (MonadMask m, MonadIO m, S.MonadAsync m)
+                                       => FilePath
+                                       -> S.SerialT m FilePath
+getDirectoryContentsRecursiveDFSUnsafe fp = go ""
+ where
+  go cd = flip S.concatMap (S.unfold unfoldDirContents (fp </> cd)) $ \(t, f) ->
+    if | t == FD.dtDir -> go (cd </> f)
+       | otherwise     -> pure (cd </> f)
+
+
+getDirectoryContentsRecursiveUnfold :: (MonadMask m, MonadIO m, S.MonadAsync m) => Unfold m FilePath FilePath
+getDirectoryContentsRecursiveUnfold = Unfold step (\s -> return (s, Nothing, [""]))
+ where
+  {-# INLINE [0] step #-}
+  step (_, Nothing, []) = return D.Stop
+
+  step (topdir, Just (cdir, dirstream, finalizer), dirs) = flip onException (runIOFinalizer finalizer) $ do
+    (dt, f) <- liftIO $ readDirEnt dirstream
+    if | FD.dtUnknown == dt -> do
+           runIOFinalizer finalizer
+           return $ D.Skip (topdir, Nothing, dirs)
+       | f == "." || f == ".."
+                        -> return $ D.Skip               (topdir, Just (cdir, dirstream, finalizer), dirs)
+       | FD.dtDir == dt -> return $ D.Skip               (topdir, Just (cdir, dirstream, finalizer), (cdir </> f):dirs)
+       | otherwise      -> return $ D.Yield (cdir </> f) (topdir, Just (cdir, dirstream, finalizer), dirs)
+
+  step (topdir, Nothing, dir:dirs) = do
+    (s, f) <- acquire (topdir </> dir)
+    return $ D.Skip (topdir, Just (dir, s, f), dirs)
+
+  acquire dir =
+    withRunInIO $ \run -> mask_ $ run $ do
+        dirstream <- liftIO $ openDirStream dir
+        ref <- newIOFinalizer (liftIO $ closeDirStream dirstream)
+        return (dirstream, ref)
+
+getDirectoryContentsRecursiveBFSUnsafe :: (MonadMask m, MonadIO m, S.MonadAsync m)
+                                       => FilePath
+                                       -> S.SerialT m FilePath
+getDirectoryContentsRecursiveBFSUnsafe = S.unfold getDirectoryContentsRecursiveUnfold
+
+
--- a/lib/GHCup/Prelude/File/Posix/Foreign.hsc
+++ b/lib/GHCup/Prelude/File/Posix/Foreign.hsc
@@ -0,0 +1,58 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+module GHCup.Prelude.File.Posix.Foreign where
+
+import Data.Bits
+import Data.List (foldl')
+import Foreign.C.Types
+
+#include <limits.h>
+#include <stdlib.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+newtype DirType = DirType Int deriving (Eq, Show)
+data Flags = Flags Int | UnsupportedFlag String deriving (Eq, Show)
+
+unFlags :: Flags -> Int
+unFlags (Flags i) = i
+unFlags (UnsupportedFlag name) = error (name ++ " is not supported on this platform")
+
+-- |Returns @True@ if posix-paths was compiled with support for the provided
+-- flag. (As of this writing, the only flag for which this check may be
+-- necessary is 'oCloexec'; all other flags will always yield @True@.)
+isSupported :: Flags -> Bool
+isSupported (Flags _) = True
+isSupported _ = False
+
+-- |@O_CLOEXEC@ is not supported on every POSIX platform. Use
+-- @'isSupported' oCloexec@ to determine if support for @O_CLOEXEC@ was
+-- compiled into your version of posix-paths. (If not, using @oCloexec@ will
+-- throw an exception.)
+oCloexec :: Flags
+#ifdef O_CLOEXEC
+oCloexec = Flags #{const O_CLOEXEC}
+#else
+{-# WARNING oCloexec
+    "This version of posix-paths was compiled without @O_CLOEXEC@ support." #-}
+oCloexec = UnsupportedFlag "O_CLOEXEC"
+#endif
+
+
+
+-- If these enum declarations occur earlier in the file, haddock
+-- gets royally confused about the above doc comments.
+-- Probably http://trac.haskell.org/haddock/ticket/138
+
+#{enum DirType, DirType, DT_BLK, DT_CHR, DT_DIR, DT_FIFO, DT_LNK, DT_REG, DT_SOCK, DT_UNKNOWN}
+
+#{enum Flags, Flags, O_APPEND, O_ASYNC, O_CREAT, O_DIRECTORY, O_EXCL, O_NOCTTY, O_NOFOLLOW, O_NONBLOCK, O_RDONLY, O_WRONLY, O_RDWR, O_SYNC, O_TRUNC}
+
+pathMax :: Int
+pathMax = #{const PATH_MAX}
+
+unionFlags :: [Flags] -> CInt
+unionFlags = fromIntegral . foldl' ((. unFlags) . (.|.)) 0
+
--- a/lib/GHCup/Prelude/File/Posix/Traversals.hs
+++ b/lib/GHCup/Prelude/File/Posix/Traversals.hs
@@ -0,0 +1,92 @@
+{-# LANGUAGE CApiFFI #-}
+{-# LANGUAGE CPP #-}
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE ViewPatterns #-}
+
+{-# OPTIONS_GHC -Wall #-}
+
+
+module GHCup.Prelude.File.Posix.Traversals (
+-- lower-level stuff
+  readDirEnt
+, unpackDirStream
+) where
+
+
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>))
+#endif
+import GHCup.Prelude.File.Posix.Foreign
+
+import Unsafe.Coerce (unsafeCoerce)
+import Foreign.C.Error
+import Foreign.C.String
+import Foreign.C.Types
+import Foreign.Ptr
+import Foreign.Storable
+import System.Posix
+import Foreign (alloca)
+import System.Posix.Internals (peekFilePath)
+
+
+
+
+
+----------------------------------------------------------
+-- dodgy stuff
+
+type CDir = ()
+type CDirent = ()
+
+-- Posix doesn't export DirStream, so to re-use that type we need to use
+-- unsafeCoerce.  It's just a newtype, so this is a legitimate usage.
+-- ugly trick.
+unpackDirStream :: DirStream -> Ptr CDir
+unpackDirStream = unsafeCoerce
+
+-- the __hscore_* functions are defined in the unix package.  We can import them and let
+-- the linker figure it out.
+foreign import ccall unsafe "__hscore_readdir"
+  c_readdir  :: Ptr CDir -> Ptr (Ptr CDirent) -> IO CInt
+
+foreign import ccall unsafe "__hscore_free_dirent"
+  c_freeDirEnt  :: Ptr CDirent -> IO ()
+
+foreign import ccall unsafe "__hscore_d_name"
+  c_name :: Ptr CDirent -> IO CString
+
+foreign import ccall unsafe "__posixdir_d_type"
+  c_type :: Ptr CDirent -> IO DirType
+
+----------------------------------------------------------
+-- less dodgy but still lower-level
+
+
+readDirEnt :: DirStream -> IO (DirType, FilePath)
+readDirEnt (unpackDirStream -> dirp) =
+  alloca $ \ptr_dEnt  -> loop ptr_dEnt
+ where
+  loop ptr_dEnt = do
+    resetErrno
+    r <- c_readdir dirp ptr_dEnt
+    if r == 0
+       then do
+         dEnt <- peek ptr_dEnt
+         if dEnt == nullPtr
+            then return (dtUnknown, mempty)
+            else do
+                 dName <- c_name dEnt >>= peekFilePath
+                 dType <- c_type dEnt
+                 c_freeDirEnt dEnt
+                 return (dType, dName)
+       else do
+         errno <- getErrno
+         if errno == eINTR
+            then loop ptr_dEnt
+            else do
+                 let (Errno eo) = errno
+                 if eo == 0
+                    then return (dtUnknown, mempty)
+                    else throwErrno "readDirEnt"
+
--- a/lib/GHCup/Prelude/File/Search.hs
+++ b/lib/GHCup/Prelude/File/Search.hs
@@ -1,13 +1,13 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE FlexibleContexts  #-}

-module GHCup.Utils.File.Common (
-  module GHCup.Utils.File.Common
+module GHCup.Prelude.File.Search (
+  module GHCup.Prelude.File.Search
  , ProcessError(..)
  , CapturedProcess(..)
  ) where

-import           GHCup.Utils.Prelude
 import           GHCup.Types(ProcessError(..), CapturedProcess(..))

 import           Control.Monad.Reader
@@ -15,15 +15,19 @@ import           Data.Maybe
 import           Data.Text               ( Text )
 import           Data.Void
 import           GHC.IO.Exception
-import           Optics                  hiding ((<|), (|>))
-import           System.Directory        hiding (findFiles)
+import           System.Directory hiding ( removeDirectory
+                                         , removeDirectoryRecursive
+                                         , removePathForcibly
+                                         , findFiles
+                                         )
 import           System.FilePath
-import           Text.PrettyPrint.HughesPJClass hiding ( (<>) )
 import           Text.Regex.Posix

+
 import qualified Data.Text                     as T
-import qualified Data.ByteString.Lazy          as BL
 import qualified Text.Megaparsec               as MP
+import Control.Exception.Safe (handleIO)
+import System.Directory.Internal.Prelude (ioeGetErrorType)



@@ -35,7 +39,7 @@ searchPath paths needle = go paths
 where
  go [] = pure Nothing
  go (x : xs) =
-    hideErrorDefM [InappropriateType, PermissionDenied, NoSuchThing] (go xs)
+    handleIO (\e -> if ioeGetErrorType e `elem` [InappropriateType, PermissionDenied, NoSuchThing] then go xs else ioError e)
      $ do
          contents <- listDirectory x
          findM (isMatch x) contents >>= \case
@@ -49,6 +53,12 @@ searchPath paths needle = go paths
  isExecutable :: FilePath -> IO Bool
  isExecutable file = executable <$> getPermissions file

+  -- TODO: inlined from GHCup.Prelude
+  findM ~p = foldr (\x -> ifM (p x) (pure $ Just x)) (pure Nothing)
+  ifM ~b ~t ~f = do
+    b' <- b
+    if b' then t else f
+

 -- | Check wether a binary is shadowed by another one that comes before
 -- it in PATH. Returns the path to said binary, if any.
@@ -96,10 +106,6 @@ findFiles path regex = do
  contents <- listDirectory path
  pure $ filter (match regex) contents

-findFilesDeep :: FilePath -> Regex -> IO [FilePath]
-findFilesDeep path regex = do
-  contents <- getDirectoryContentsRecursive path
-  pure $ filter (match regex) contents

 findFiles' :: FilePath -> MP.Parsec Void Text a -> IO [FilePath]
 findFiles' path parser = do
@@ -107,5 +113,3 @@ findFiles' path parser = do
  pure $ filter (\fp -> either (const False) (const True) $ MP.parse parser "" (T.pack fp)) contents


-checkFileAlreadyExists :: (MonadIO m) => FilePath -> m Bool
-checkFileAlreadyExists fp = liftIO $ doesFileExist fp
--- a/lib/GHCup/Prelude/File/Windows.hs
+++ b/lib/GHCup/Prelude/File/Windows.hs
@@ -0,0 +1,311 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE DataKinds  #-}
+
+{-|
+Module      : GHCup.Utils.File.Windows
+Description : File and directory handling for windows
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : Windows
+-}
+module GHCup.Prelude.File.Windows where
+
+import           GHCup.Utils.Dirs
+import           GHCup.Prelude.Internal
+
+import           Control.Exception.Safe
+import           Control.Monad
+import           Control.Monad.Reader
+import           Data.List
+import qualified GHC.Unicode                  as U
+import           System.FilePath
+import qualified System.IO.Error              as IOE
+
+import qualified System.Win32.Info             as WS
+import qualified System.Win32.File             as WS
+
+import qualified Streamly.Internal.Data.Stream.StreamD.Type
+                                               as D
+import           Streamly.Internal.Data.Unfold.Type hiding ( concatMap )
+import           Data.Bits ((.&.))
+import qualified Streamly.Prelude              as S
+import qualified Streamly.Internal.Data.Unfold as U
+import           Streamly.Internal.Control.Concurrent ( withRunInIO )
+import           Streamly.Internal.Data.IOFinalizer   ( newIOFinalizer, runIOFinalizer )
+
+
+
+-- | On unix, we can use symlinks, so we just get the
+-- symbolic link target.
+--
+-- On windows, we have to emulate symlinks via shims,
+-- see 'createLink'.
+getLinkTarget :: FilePath -> IO FilePath
+getLinkTarget fp = do
+  content <- readFile (dropExtension fp <.> "shim")
+  [p] <- pure . filter ("path = " `isPrefixOf`) . lines $ content
+  pure $ stripNewline $ dropPrefix "path = " p
+
+
+-- | Checks whether the path is a link.
+pathIsLink :: FilePath -> IO Bool
+pathIsLink fp = doesPathExist (dropExtension fp <.> "shim")
+
+
+
+chmod_755 :: MonadIO m => FilePath -> m ()
+chmod_755 fp =
+  let perm = setOwnerWritable True emptyPermissions
+  in liftIO $ setPermissions fp perm
+
+
+-- | Checks whether the binary is a broken link.
+isBrokenSymlink :: FilePath -> IO Bool
+isBrokenSymlink fp = do
+  b <- pathIsLink fp
+  if b
+  then do
+    tfp <- getLinkTarget fp
+    not <$> doesPathExist
+      -- this drops 'symDir' if 'tfp' is absolute
+      (takeDirectory fp </> tfp)
+  else pure False
+
+
+copyFile :: FilePath   -- ^ source file
+         -> FilePath   -- ^ destination file
+         -> Bool       -- ^ fail if file exists
+         -> IO ()
+copyFile = WS.copyFile
+
+deleteFile :: FilePath -> IO ()
+deleteFile = WS.deleteFile
+
+
+install :: FilePath -> FilePath -> Bool -> IO ()
+install = copyFile
+
+
+moveFile :: FilePath -> FilePath -> IO ()
+moveFile from to = WS.moveFileEx from (Just to) 0
+
+
+moveFilePortable :: FilePath -> FilePath -> IO ()
+moveFilePortable = WS.moveFile
+
+
+removeEmptyDirectory :: FilePath -> IO ()
+removeEmptyDirectory = WS.removeDirectory
+
+
+unfoldDirContents :: (S.MonadAsync m, MonadIO m, MonadCatch m, MonadMask m) => Unfold m FilePath (WS.FileAttributeOrFlag, FilePath)
+unfoldDirContents = U.bracket alloc dealloc (Unfold step return)
+ where
+  {-# INLINE [0] step #-}
+  step (_, False, _, _) = return D.Stop
+  step (topdir, True, h, fd) = flip onException (liftIO $ WS.findClose h) $ do
+    f <- liftIO $ WS.getFindDataFileName fd
+    more <- liftIO $ WS.findNextFile h fd
+
+    -- can't get file attribute from FindData yet (needs Win32 PR)
+    fattr <- liftIO $ WS.getFileAttributes (topdir </> f)
+
+    if | f == "." || f == ".." -> return $ D.Skip             (topdir, more, h, fd)
+       | otherwise             -> return $ D.Yield (fattr, f) (topdir, more, h, fd)
+
+  alloc topdir = do
+    query <- liftIO $ furnishPath (topdir </> "*")
+    (h, fd) <- liftIO $ WS.findFirstFile query
+    pure (topdir, True, h, fd)
+
+  dealloc (_, _, fd, _) = liftIO $ WS.findClose fd
+
+
+getDirectoryContentsRecursiveDFSUnsafe :: (MonadCatch m, S.MonadAsync m, MonadMask m, S.IsStream t)
+                                       => FilePath
+                                       -> t m FilePath
+getDirectoryContentsRecursiveDFSUnsafe fp = go ""
+ where
+  isDir attrs = attrs .&. WS.fILE_ATTRIBUTE_DIRECTORY /= 0
+
+  go cd = flip S.concatMap (S.unfold unfoldDirContents (fp </> cd)) $ \(t, f) ->
+    if | isDir t   -> go (cd </> f)
+       | otherwise -> pure (cd </> f)
+
+
+getDirectoryContentsRecursiveUnfold :: (MonadCatch m, S.MonadAsync m, MonadMask m) => Unfold m FilePath FilePath
+getDirectoryContentsRecursiveUnfold = Unfold step init'
+ where
+  {-# INLINE [0] step #-}
+  step (_, Nothing, []) = return D.Stop
+
+  step (topdir, state@(Just (cdir, (h, findData, ref))), dirs) = flip onException (runIOFinalizer ref) $ do
+    f <- liftIO $ WS.getFindDataFileName findData
+
+    more <- liftIO $ WS.findNextFile h findData
+    when (not more) $ runIOFinalizer ref
+    let nextState = if more then state else Nothing
+
+    -- can't get file attribute from FindData yet (needs Win32 PR)
+    fattr <- liftIO $ WS.getFileAttributes (topdir </> cdir </> f)
+
+    if | f == "." || f == ".." -> return $ D.Skip               (topdir, nextState, dirs)
+       | isDir fattr           -> return $ D.Skip               (topdir, nextState, (cdir </> f):dirs)
+       | otherwise             -> return $ D.Yield (cdir </> f) (topdir, nextState, dirs)
+
+  step (topdir, Nothing, dir:dirs) = do
+    (h, findData, ref) <- acquire (topdir </> dir)
+    return $ D.Skip (topdir, Just (dir, (h, findData, ref)), dirs)
+
+  init' topdir = do
+    (h, findData, ref) <- acquire topdir
+    return (topdir, Just ("", (h, findData, ref)), [])
+
+  isDir attrs = attrs .&. WS.fILE_ATTRIBUTE_DIRECTORY /= 0
+
+  acquire dir = do
+    query <- liftIO $ furnishPath (dir </> "*")
+    withRunInIO $ \run -> mask_ $ run $ do
+        (h, findData) <- liftIO $ WS.findFirstFile query
+        ref <- newIOFinalizer (liftIO $ WS.findClose h)
+        return (h, findData, ref)
+
+
+getDirectoryContentsRecursiveBFSUnsafe :: (MonadMask m, MonadIO m, S.MonadAsync m)
+                                       => FilePath
+                                       -> S.SerialT m FilePath
+getDirectoryContentsRecursiveBFSUnsafe = S.unfold getDirectoryContentsRecursiveUnfold
+
+
+
+    --------------------------------------
+    --[ Inlined from directory package ]--
+    --------------------------------------
+
+
+furnishPath :: FilePath -> IO FilePath
+furnishPath path =
+  (toExtendedLengthPath <$> rawPrependCurrentDirectory path)
+    `IOE.catchIOError` \ _ ->
+      pure path
+
+
+toExtendedLengthPath :: FilePath -> FilePath
+toExtendedLengthPath path
+  | isRelative path = simplifiedPath
+  | otherwise =
+      case simplifiedPath of
+        '\\' : '?'  : '?' : '\\' : _ -> simplifiedPath
+        '\\' : '\\' : '?' : '\\' : _ -> simplifiedPath
+        '\\' : '\\' : '.' : '\\' : _ -> simplifiedPath
+        '\\' : subpath@('\\' : _) -> "\\\\?\\UNC" <> subpath
+        _ -> "\\\\?\\" <> simplifiedPath
+  where simplifiedPath = simplify path
+
+
+simplify :: FilePath -> FilePath
+simplify = simplifyWindows
+
+simplifyWindows :: FilePath -> FilePath
+simplifyWindows "" = ""
+simplifyWindows path =
+  case drive' of
+    "\\\\?\\" -> drive' <> subpath
+    _ -> simplifiedPath
+  where
+    simplifiedPath = joinDrive drive' subpath'
+    (drive, subpath) = splitDrive path
+    drive' = upperDrive (normaliseTrailingSep (normalisePathSeps drive))
+    subpath' = appendSep . avoidEmpty . prependSep . joinPath .
+               stripPardirs . expandDots . skipSeps .
+               splitDirectories $ subpath
+
+    upperDrive d = case d of
+      c : ':' : s | U.isAlpha c && all isPathSeparator s -> U.toUpper c : ':' : s
+      _ -> d
+    skipSeps = filter (not . (`elem` (pure <$> pathSeparators)))
+    stripPardirs | pathIsAbsolute || subpathIsAbsolute = dropWhile (== "..")
+                 | otherwise = id
+    prependSep | subpathIsAbsolute = (pathSeparator :)
+               | otherwise = id
+    avoidEmpty | not pathIsAbsolute
+                 && (null drive || hasTrailingPathSep) -- prefer "C:" over "C:."
+                 = emptyToCurDir
+               | otherwise = id
+    appendSep p | hasTrailingPathSep
+                  && not (pathIsAbsolute && null p)
+                  = addTrailingPathSeparator p
+                | otherwise = p
+    pathIsAbsolute = not (isRelative path)
+    subpathIsAbsolute = any isPathSeparator (take 1 subpath)
+    hasTrailingPathSep = hasTrailingPathSeparator subpath
+
+emptyToCurDir :: FilePath -> FilePath
+emptyToCurDir ""   = "."
+emptyToCurDir path = path
+
+normaliseTrailingSep :: FilePath -> FilePath
+normaliseTrailingSep path = do
+  let path' = reverse path
+  let (sep, path'') = span isPathSeparator path'
+  let addSep = if null sep then id else (pathSeparator :)
+  reverse (addSep path'')
+
+normalisePathSeps :: FilePath -> FilePath
+normalisePathSeps p = (\ c -> if isPathSeparator c then pathSeparator else c) <$> p
+
+expandDots :: [FilePath] -> [FilePath]
+expandDots = reverse . go []
+  where
+    go ys' xs' =
+      case xs' of
+        [] -> ys'
+        x : xs ->
+          case x of
+            "." -> go ys' xs
+            ".." ->
+              case ys' of
+                [] -> go (x : ys') xs
+                ".." : _ -> go (x : ys') xs
+                _ : ys -> go ys xs
+            _ -> go (x : ys') xs
+
+rawPrependCurrentDirectory :: FilePath -> IO FilePath
+rawPrependCurrentDirectory path
+  | isRelative path =
+    ((`ioeAddLocation` "prependCurrentDirectory") .
+     (`IOE.ioeSetFileName` path)) `IOE.modifyIOError` do
+      getFullPathName path
+  | otherwise = pure path
+
+ioeAddLocation :: IOError -> String -> IOError
+ioeAddLocation e loc = do
+  IOE.ioeSetLocation e newLoc
+  where
+    newLoc = loc <> if null oldLoc then "" else ":" <> oldLoc
+    oldLoc = IOE.ioeGetLocation e
+
+getFullPathName :: FilePath -> IO FilePath
+getFullPathName path =
+  fromExtendedLengthPath <$> WS.getFullPathName (toExtendedLengthPath path)
+
+fromExtendedLengthPath :: FilePath -> FilePath
+fromExtendedLengthPath ePath =
+  case ePath of
+    '\\' : '\\' : '?' : '\\' : path ->
+      case path of
+        'U' : 'N' : 'C' : subpath@('\\' : _) -> "\\" <> subpath
+        drive : ':' : subpath
+          -- if the path is not "regular", then the prefix is necessary
+          -- to ensure the path is interpreted literally
+          | U.isAlpha drive && U.isAscii drive && isPathRegular subpath -> path
+        _ -> ePath
+    _ -> ePath
+  where
+    isPathRegular path =
+      not ('/' `elem` path ||
+           "." `elem` splitDirectories path ||
+           ".." `elem` splitDirectories path)
--- a/lib/GHCup/Prelude/Internal.hs
+++ b/lib/GHCup/Prelude/Internal.hs
@@ -7,7 +7,7 @@
 {-# LANGUAGE TypeOperators       #-}

 {-|
-Module      : GHCup.Utils.Prelude
+Module      : GHCup.Prelude.Internal
 Description : MegaParsec utilities
 Copyright   : (c) Julian Ospald, 2020
 License     : LGPL-3.0
@@ -15,27 +15,11 @@ Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : portable

-GHCup specific prelude. Lots of Excepts functionality.
+Stuff that doesn't need GHCup modules, so we can avoid
+recursive imports.
 -}
-module GHCup.Utils.Prelude
-  (module GHCup.Utils.Prelude,
-#if defined(IS_WINDOWS)
-   module GHCup.Utils.Prelude.Windows
-#else
-   module GHCup.Utils.Prelude.Posix
-#endif
-  )
-where
+module GHCup.Prelude.Internal where

-import           GHCup.Types
-import           GHCup.Errors
-import           GHCup.Types.Optics
-import {-# SOURCE #-} GHCup.Utils.Logger (logWarn)
-#if defined(IS_WINDOWS)
-import           GHCup.Utils.Prelude.Windows
-#else
-import           GHCup.Utils.Prelude.Posix
-#endif

 import           Control.Applicative
 import           Control.Exception.Safe
@@ -44,22 +28,15 @@ import           Control.Monad.IO.Class
 import           Control.Monad.Reader
 import           Data.Bifunctor
 import           Data.ByteString                ( ByteString )
-import           Data.List                      ( nub, intercalate, stripPrefix, isPrefixOf, dropWhileEnd, intersperse )
+import           Data.List                      ( intercalate, stripPrefix, isPrefixOf, dropWhileEnd )
 import           Data.Maybe
-import           Data.Foldable
-import           Data.List.NonEmpty             ( NonEmpty( (:|) ))
 import           Data.String
 import           Data.Text                      ( Text )
 import           Data.Versions
 import           Data.Word8                  hiding ( isDigit )
 import           Haskus.Utils.Types.List
 import           Haskus.Utils.Variant.Excepts
-import           Text.PrettyPrint.HughesPJClass ( prettyShow, Pretty )
 import           System.IO.Error
-import           System.IO.Temp
-import           System.IO.Unsafe
-import           System.Directory
-import           System.FilePath

 import           Control.Retry
 import           GHC.IO.Exception
@@ -68,7 +45,6 @@ import qualified Data.ByteString               as B
 import qualified Data.ByteString.Lazy          as L
 import qualified Data.Strict.Maybe             as S
 import qualified Data.List.Split               as Split
-import qualified Data.List.NonEmpty            as NE
 import qualified Data.Text                     as T
 import qualified Data.Text.Encoding            as E
 import qualified Data.Text.Encoding.Error      as E
@@ -78,6 +54,7 @@ import qualified Data.Text.Lazy.Builder.Int    as B
 import qualified Data.Text.Lazy.Encoding       as TLE


+
 -- $setup
 -- >>> import Data.ByteString.Internal (c2w, w2c)
 -- >>> import Test.QuickCheck
@@ -181,13 +158,6 @@ lEM' :: forall e' e es a m
     -> Excepts es m a
 lEM' f em = lift em >>= lE . first f

-- for some obscure reason... this won't type-check if we move it to a different module
-catchWarn :: forall es m env . ( Pretty (V es)
-                             , MonadReader env m
-                             , HasLog env
-                             , MonadIO m
-                             , Monad m) => Excepts es m () -> Excepts '[] m ()
-catchWarn = catchAllE @_ @es (\v -> lift $ logWarn (T.pack . prettyShow $ v))

 fromEither :: Either a b -> VEither '[a] b
 fromEither = either (VLeft . V) VRight
@@ -308,56 +278,6 @@ intToText :: Integral a => a -> T.Text
 intToText = TL.toStrict . B.toLazyText . B.decimal


-pvpToVersion :: MonadThrow m => PVP -> Text -> m Version
-pvpToVersion pvp_ rest =
-  either (\_ -> throwM $ ParseError "Couldn't convert PVP to Version") pure . version . (<> rest) . prettyPVP $ pvp_
-
-- | Convert a version to a PVP and unparsable rest.
--
-- -- prop> \v -> let (Just (pvp', r)) = versionToPVP v in pvpToVersion pvp' r === Just v
-versionToPVP :: MonadThrow m => Version -> m (PVP, Text)
-versionToPVP (Version (Just _) _ _ _) = throwM $ ParseError "Unexpected epoch"
-versionToPVP v = either (\_ -> (, rest v) <$> alternative v) (pure . (, mempty)) . pvp . prettyVer $ v
- where
-  alternative :: MonadThrow m => Version -> m PVP
-  alternative v' = case NE.takeWhile isDigit (_vChunks v') of
-    [] -> throwM $ ParseError "Couldn't convert Version to PVP"
-    xs -> pure $ pvpFromList (unsafeDigit <$> xs)
-
-  rest :: Version -> Text
-  rest (Version _ cs pr me) =
-    let chunks = NE.dropWhile isDigit cs
-        ver = intersperse (T.pack ".") . chunksAsT $ chunks
-        me' = maybe [] (\m -> [T.pack "+",m]) me
-        pr' = foldable [] (T.pack "-" :) $ intersperse (T.pack ".") (chunksAsT pr)
-        prefix = case (ver, pr', me') of
-                   (_:_, _, _) -> T.pack "."
-                   _           -> T.pack ""
-    in prefix <> mconcat (ver <> pr' <> me')
-   where
-    chunksAsT :: Functor t => t VChunk -> t Text
-    chunksAsT = fmap (foldMap f)
-      where
-        f :: VUnit -> Text
-        f (Digits i) = T.pack $ show i
-        f (Str s)    = s
-
-    foldable :: Foldable f => f b -> (f a -> f b) -> f a -> f b
-    foldable d g f | null f    = d
-                   | otherwise = g f
-
-
-
-  isDigit :: VChunk -> Bool
-  isDigit (Digits _ :| []) = True
-  isDigit _                = False
-
-  unsafeDigit :: VChunk -> Int
-  unsafeDigit (Digits x :| []) = fromIntegral x
-  unsafeDigit _ = error "unsafeDigit: wrong input"
-
-pvpFromList :: [Int] -> PVP
-pvpFromList = PVP . NE.fromList . fmap fromIntegral

 -- | Safe 'decodeUtf8With'. Replaces an invalid input byte with
 -- the Unicode replacement character U+FFFD.
@@ -376,167 +296,6 @@ escapeVerRex = B.pack . go . B.unpack . verToBS
  go (x : xs) | x == _period = [_backslash, _period] ++ go xs
              | otherwise    = x : go xs

-- | More permissive version of 'createDirRecursive'. This doesn't
-- error when the destination is a symlink to a directory.
-createDirRecursive' :: FilePath -> IO ()
-createDirRecursive' p =
-  handleIO (\e -> if isAlreadyExistsError e then isSymlinkDir e else throwIO e)
-    . createDirectoryIfMissing True
-    $ p
-
- where
-  isSymlinkDir e = do
-    ft <- pathIsSymbolicLink p
-    case ft of
-      True -> do
-        rp <- canonicalizePath p
-        rft <- doesDirectoryExist rp
-        case rft of
-          True -> pure ()
-          _ -> throwIO e
-      _ -> throwIO e
-
-
-- | Recursively copy the contents of one directory to another path.
--
-- This is a rip-off of Cabal library.
-copyDirectoryRecursive :: FilePath -> FilePath -> (FilePath -> FilePath -> IO ()) -> IO ()
-copyDirectoryRecursive srcDir destDir doCopy = do
-  srcFiles <- getDirectoryContentsRecursive srcDir
-  copyFilesWith destDir [ (srcDir, f)
-                          | f <- srcFiles ]
-  where
-    -- | Common implementation of 'copyFiles', 'installOrdinaryFiles',
-    -- 'installExecutableFiles' and 'installMaybeExecutableFiles'.
-    copyFilesWith :: FilePath -> [(FilePath, FilePath)] -> IO ()
-    copyFilesWith targetDir srcFiles = do
-
-      -- Create parent directories for everything
-      let dirs = map (targetDir </>) . nub . map (takeDirectory . snd) $ srcFiles
-      traverse_ (createDirectoryIfMissing True) dirs
-
-      -- Copy all the files
-      sequence_ [ let src  = srcBase   </> srcFile
-                      dest = targetDir </> srcFile
-                   in doCopy src dest
-                | (srcBase, srcFile) <- srcFiles ]
-
-
-- | List all the files in a directory and all subdirectories.
--
-- The order places files in sub-directories after all the files in their
-- parent directories. The list is generated lazily so is not well defined if
-- the source directory structure changes before the list is used.
--
-getDirectoryContentsRecursive :: FilePath -> IO [FilePath]
-getDirectoryContentsRecursive topdir = recurseDirectories [""]
-  where
-    recurseDirectories :: [FilePath] -> IO [FilePath]
-    recurseDirectories []         = return []
-    recurseDirectories (dir:dirs) = unsafeInterleaveIO $ do
-      (files, dirs') <- collect [] [] =<< getDirectoryContents (topdir </> dir)
-      files' <- recurseDirectories (dirs' ++ dirs)
-      return (files ++ files')
-
-      where
-        collect files dirs' []              = return (reverse files
-                                                     ,reverse dirs')
-        collect files dirs' (entry:entries) | ignore entry
-                                            = collect files dirs' entries
-        collect files dirs' (entry:entries) = do
-          let dirEntry = dir </> entry
-          isDirectory <- doesDirectoryExist (topdir </> dirEntry)
-          if isDirectory
-            then collect files (dirEntry:dirs') entries
-            else collect (dirEntry:files) dirs' entries
-
-        ignore ['.']      = True
-        ignore ['.', '.'] = True
-        ignore _          = False
-
-
-- https://github.com/haskell/directory/issues/110
-- https://github.com/haskell/directory/issues/96
-- https://www.sqlite.org/src/info/89f1848d7f
-recyclePathForcibly :: ( MonadIO m
-                       , MonadReader env m
-                       , HasDirs env
-                       , MonadMask m
-                       )
-                    => FilePath
-                    -> m ()
-recyclePathForcibly fp
-  | isWindows = do
-      Dirs { recycleDir } <- getDirs
-      tmp <- liftIO $ createTempDirectory recycleDir "recyclePathForcibly"
-      let dest = tmp </> takeFileName fp
-      liftIO (moveFile fp dest)
-          `catch`
-          (\e -> if | isDoesNotExistError e -> pure ()
-                    | isPermissionError e || ioeGetErrorType e == UnsupportedOperation {- EXDEV on windows -} -> recover (liftIO $ removePathForcibly fp)
-                    | otherwise -> throwIO e)
-          `finally`
-            liftIO (handleIO (\_ -> pure ()) $ removePathForcibly tmp)
-  | otherwise = liftIO $ removePathForcibly fp
-
-
-rmPathForcibly :: ( MonadIO m
-                  , MonadMask m
-                  )
-               => FilePath
-               -> m ()
-rmPathForcibly fp
-  | isWindows = recover (liftIO $ removePathForcibly fp)
-  | otherwise = liftIO $ removePathForcibly fp
-
-
-rmDirectory :: (MonadIO m, MonadMask m)
-            => FilePath
-            -> m ()
-rmDirectory fp
-  | isWindows = recover (liftIO $ removeDirectory fp)
-  | otherwise = liftIO $ removeDirectory fp
-
-
-- https://www.sqlite.org/src/info/89f1848d7f
-- https://github.com/haskell/directory/issues/96
-recycleFile :: ( MonadIO m
-               , MonadMask m
-               , MonadReader env m
-               , HasDirs env
-               )
-            => FilePath
-            -> m ()
-recycleFile fp
-  | isWindows = do
-      Dirs { recycleDir } <- getDirs
-      liftIO $ whenM (doesDirectoryExist fp) $ ioError (IOError Nothing InappropriateType "recycleFile" "" Nothing (Just fp))
-      tmp <- liftIO $ createTempDirectory recycleDir "recycleFile"
-      let dest = tmp </> takeFileName fp
-      liftIO (moveFile fp dest)
-        `catch`
-          (\e -> if isPermissionError e || ioeGetErrorType e == UnsupportedOperation {- EXDEV on windows -} then recover (liftIO $ removePathForcibly fp) else throwIO e)
-        `finally`
-          liftIO (handleIO (\_ -> pure ()) $ removePathForcibly tmp)
-  | otherwise = liftIO $ removeFile fp
-
-
-rmFile :: ( MonadIO m
-          , MonadMask m
-          )
-      => FilePath
-      -> m ()
-rmFile fp
-  | isWindows = recover (liftIO $ removeFile fp)
-  | otherwise = liftIO $ removeFile fp
-
-
-rmDirectoryLink :: (MonadIO m, MonadMask m, MonadReader env m, HasDirs env)
-                => FilePath
-                -> m ()
-rmDirectoryLink fp
-  | isWindows = recover (liftIO $ removeDirectoryLink fp)
-  | otherwise = liftIO $ removeDirectoryLink fp


 recover :: (MonadIO m, MonadMask m) => m a -> m a
@@ -549,10 +308,6 @@ recover action =
    (\_ -> action)


-copyFileE :: (CopyError :< xs, MonadCatch m, MonadIO m) => FilePath -> FilePath -> Excepts xs m ()
-copyFileE from = handleIO (throwE . CopyError . show) . liftIO . copyFile from
-
-
 -- | Gathering monoidal values
 --
 -- >>> traverseFold (pure . (:["0"])) ["1","2"]
@@ -762,4 +517,3 @@ breakOn :: Eq a => [a] -> [a] -> ([a], [a])
 breakOn needle haystack | needle `isPrefixOf` haystack = ([], haystack)
 breakOn _ [] = ([], [])
 breakOn needle (x:xs) = first (x:) $ breakOn needle xs
-
--- a/lib/GHCup/Prelude/Logger.hs
+++ b/lib/GHCup/Prelude/Logger.hs
@@ -0,0 +1,61 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE DataKinds        #-}
+{-# LANGUAGE OverloadedStrings   #-}
+
+{-|
+Module      : GHCup.Utils.Logger
+Description : logger definition
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+
+Here we define our main logger.
+-}
+module GHCup.Prelude.Logger
+  ( module GHCup.Prelude.Logger
+  , module GHCup.Prelude.Logger.Internal
+  )
+where
+
+import           GHCup.Prelude.Logger.Internal
+import           GHCup.Types
+import           GHCup.Types.Optics
+import           GHCup.Utils.Dirs (fromGHCupPath)
+import           GHCup.Prelude.Internal
+import           GHCup.Prelude.File.Search (findFiles)
+import           GHCup.Prelude.File (recycleFile)
+import           GHCup.Prelude.String.QQ
+
+import           Control.Exception.Safe
+import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Reader
+import           Prelude                 hiding ( appendFile )
+import           System.FilePath
+import           System.IO.Error
+import           Text.Regex.Posix
+
+import qualified Data.ByteString               as B
+
+
+
+initGHCupFileLogging :: ( MonadReader env m
+                        , HasDirs env
+                        , MonadIO m
+                        , MonadMask m
+                        ) => m FilePath
+initGHCupFileLogging = do
+  Dirs { logsDir } <- getDirs
+  let logfile = fromGHCupPath logsDir </> "ghcup.log"
+  logFiles <- liftIO $ findFiles
+    (fromGHCupPath logsDir)
+    (makeRegexOpts compExtended
+                   execBlank
+                   ([s|^.*\.log$|] :: B.ByteString)
+    )
+  forM_ logFiles $ hideError doesNotExistErrorType . recycleFile . (fromGHCupPath logsDir </>)
+
+  liftIO $ writeFile logfile ""
+  pure logfile
--- a/lib/GHCup/Prelude/Logger/Internal.hs
+++ b/lib/GHCup/Prelude/Logger/Internal.hs
@@ -3,7 +3,7 @@
 {-# LANGUAGE OverloadedStrings   #-}

 {-|
-Module      : GHCup.Utils.Logger
+Module      : GHCup.Utils.Logger.Internal
 Description : logger definition
 Copyright   : (c) Julian Ospald, 2020
 License     : LGPL-3.0
@@ -11,16 +11,13 @@ Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : portable

-Here we define our main logger.
+Breaking import cycles.
 -}
-module GHCup.Utils.Logger where
+module GHCup.Prelude.Logger.Internal where

 import           GHCup.Types
 import           GHCup.Types.Optics
-import {-# SOURCE #-} GHCup.Utils.File.Common (findFiles)
-import           GHCup.Utils.String.QQ

-import           Control.Exception.Safe
 import           Control.Monad
 import           Control.Monad.IO.Class
 import           Control.Monad.Reader
@@ -28,12 +25,7 @@ import           Data.Text               ( Text )
 import           Optics
 import           Prelude                 hiding ( appendFile )
 import           System.Console.Pretty
-import           System.FilePath
-import           System.IO.Error
-import           Text.Regex.Posix

-import qualified Data.ByteString               as B
-import GHCup.Utils.Prelude
 import qualified Data.Text                     as T

 logInfo :: ( MonadReader env m
@@ -91,7 +83,7 @@ logInternal logLevel msg = do
  let strs = T.split (== '\n') msg
  let out = case strs of
              [] -> T.empty
-              (x:xs) -> 
+              (x:xs) ->
                  foldr (\a b -> a <> "\n" <> b) mempty
                . ((l <> " " <> x) :)
                . fmap (\line' -> style' "[ ...   ] " <> line' )
@@ -109,22 +101,3 @@ logInternal logLevel msg = do
  let outr = lr <> " " <> msg <> "\n"
  liftIO $ fileOutter outr

-
-initGHCupFileLogging :: ( MonadReader env m
-                        , HasDirs env
-                        , MonadIO m
-                        , MonadMask m
-                        ) => m FilePath
-initGHCupFileLogging = do
-  Dirs { logsDir } <- getDirs
-  let logfile = logsDir </> "ghcup.log"
-  logFiles <- liftIO $ findFiles
-    logsDir
-    (makeRegexOpts compExtended
-                   execBlank
-                   ([s|^.*\.log$|] :: B.ByteString)
-    )
-  forM_ logFiles $ hideError doesNotExistErrorType . recycleFile . (logsDir </>)
-
-  liftIO $ writeFile logfile ""
-  pure logfile
--- a/lib/GHCup/Prelude/MegaParsec.hs
+++ b/lib/GHCup/Prelude/MegaParsec.hs
@@ -10,7 +10,7 @@ Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : portable
 -}
-module GHCup.Utils.MegaParsec where
+module GHCup.Prelude.MegaParsec where

 import           GHCup.Types

--- a/lib/GHCup/Prelude/Posix.hs
+++ b/lib/GHCup/Prelude/Posix.hs
@@ -1,4 +1,4 @@
-module GHCup.Utils.Posix where
+module GHCup.Prelude.Posix where


 -- | Enables ANSI support on windows, does nothing on unix.
@@ -12,3 +12,8 @@ module GHCup.Utils.Posix where
 enableAnsiSupport :: IO (Either String Bool)
 enableAnsiSupport = pure (Right True)

+isWindows, isNotWindows :: Bool
+isWindows = False
+isNotWindows = not isWindows
+
+
--- a/lib/GHCup/Prelude/Process.hs
+++ b/lib/GHCup/Prelude/Process.hs
@@ -0,0 +1,25 @@
+{-# LANGUAGE CPP #-}
+
+{-|
+Module      : GHCup.Utils.Process
+Description : Process handling
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+-}
+module GHCup.Prelude.Process (
+  executeOut,
+  execLogged,
+  exec,
+  toProcessError,
+) where
+
+
+#if IS_WINDOWS
+import GHCup.Prelude.Process.Windows
+#else
+import GHCup.Prelude.Process.Posix
+#endif
+
--- a/lib/GHCup/Prelude/Process/Posix.hs
+++ b/lib/GHCup/Prelude/Process/Posix.hs
@@ -1,29 +1,31 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE DataKinds  #-}
+{-# LANGUAGE MultiWayIf  #-}
+{-# LANGUAGE CApiFFI #-}

 {-|
 Module      : GHCup.Utils.File.Posix
-Description : File and unix APIs
+Description : Process handling for unix
 Copyright   : (c) Julian Ospald, 2020
 License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
-
-This module handles file and executable handling.
-Some of these functions use sophisticated logging.
 -}
-module GHCup.Utils.File.Posix where
+module GHCup.Prelude.Process.Posix where

-import           GHCup.Utils.File.Common
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.Logger
+import           GHCup.Utils.Dirs
+import           GHCup.Prelude.File
+import           GHCup.Prelude.File.Posix
+import           GHCup.Prelude
+import           GHCup.Prelude.Logger
 import           GHCup.Types
 import           GHCup.Types.Optics

 import           Control.Concurrent
 import           Control.Concurrent.Async
-import           Control.Exception              ( evaluate )
+import qualified Control.Exception              as E
 import           Control.Exception.Safe
 import           Control.Monad
 import           Control.Monad.Reader
@@ -36,11 +38,9 @@ import           Data.List
 import           Data.Word8
 import           GHC.IO.Exception
 import           System.IO                      ( stderr )
-import           System.IO.Error
+import           System.IO.Error      hiding    ( catchIOError )
 import           System.FilePath
-import           System.Directory
 import           System.Posix.Directory
-import           System.Posix.Files
 import           System.Posix.IO
 import           System.Posix.Process           ( ProcessStatus(..) )
 import           System.Posix.Types
@@ -87,7 +87,7 @@ execLogged exe args chdir lfile env = do
  Settings {..} <- getSettings
  Dirs {..} <- getDirs
  logDebug $ T.pack $ "Running " <> exe <> " with arguments " <> show args
-  let logfile = logsDir </> lfile <> ".log"
+  let logfile = fromGHCupPath logsDir </> lfile <> ".log"
  liftIO $ bracket (openFd logfile WriteOnly (Just newFilePerms) defaultFileFlags{ append = True })
                   closeFd
                   (action verbose noColor)
@@ -262,7 +262,7 @@ captureOutStreams action = do

        -- execute the action
        a <- action
-        void $ evaluate a
+        void $ E.evaluate a

      -- close everything we don't need
      closeFd childStdoutWrite
@@ -360,42 +360,3 @@ toProcessError exe args mps = case mps of



-chmod_755 :: (MonadReader env m, HasLog env, MonadIO m) => FilePath -> m ()
-chmod_755 fp = do
-  let exe_mode =
-          nullFileMode
-            `unionFileModes` ownerExecuteMode
-            `unionFileModes` ownerReadMode
-            `unionFileModes` ownerWriteMode
-            `unionFileModes` groupExecuteMode
-            `unionFileModes` groupReadMode
-            `unionFileModes` otherExecuteMode
-            `unionFileModes` otherReadMode
-  logDebug ("chmod 755 " <> T.pack fp)
-  liftIO $ setFileMode fp exe_mode
-
-
-- |Default permissions for a new file.
-newFilePerms :: FileMode
-newFilePerms =
-  ownerWriteMode
-    `unionFileModes` ownerReadMode
-    `unionFileModes` groupWriteMode
-    `unionFileModes` groupReadMode
-    `unionFileModes` otherWriteMode
-    `unionFileModes` otherReadMode
-
-
-- | Checks whether the binary is a broken link.
-isBrokenSymlink :: FilePath -> IO Bool
-isBrokenSymlink fp = do
-  try (pathIsSymbolicLink fp) >>= \case
-    Right True -> do
-      let symDir = takeDirectory fp
-      tfp <- getSymbolicLinkTarget fp
-      not <$> doesPathExist
-        -- this drops 'symDir' if 'tfp' is absolute
-        (symDir </> tfp)
-    Right b -> pure b
-    Left e | isDoesNotExistError e -> pure False
-           | otherwise -> throwIO e
--- a/lib/GHCup/Prelude/Process/Windows.hs
+++ b/lib/GHCup/Prelude/Process/Windows.hs
@@ -1,24 +1,21 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE FlexibleContexts  #-}
+{-# LANGUAGE DataKinds  #-}

 {-|
-Module      : GHCup.Utils.File.Windows
-Description : File and windows APIs
+Module      : GHCup.Utils.Process.Windows
+Description : Process handling for windows
 Copyright   : (c) Julian Ospald, 2020
 License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : Windows
-
-This module handles file and executable handling.
-Some of these functions use sophisticated logging.
 -}
-module GHCup.Utils.File.Windows where
+module GHCup.Prelude.Process.Windows where

-import {-# SOURCE #-} GHCup.Utils ( getLinkTarget, pathIsLink )
 import           GHCup.Utils.Dirs
-import           GHCup.Utils.File.Common
-import           GHCup.Utils.Logger
+import           GHCup.Prelude.File.Search
+import           GHCup.Prelude.Logger.Internal
 import           GHCup.Types
 import           GHCup.Types.Optics

@@ -31,12 +28,11 @@ import           Data.List
 import           Foreign.C.Error
 import           GHC.IO.Exception
 import           GHC.IO.Handle
-import           System.Directory
 import           System.Environment
 import           System.FilePath
 import           System.IO
 import           System.Process
- 
+
 import qualified Control.Exception             as EX
 import qualified Data.ByteString               as BS
 import qualified Data.ByteString.Lazy          as BL
@@ -45,6 +41,7 @@ import qualified Data.Text                     as T



+
 toProcessError :: FilePath
               -> [FilePath]
               -> ExitCode
@@ -164,8 +161,8 @@ execLogged :: ( MonadReader env m
 execLogged exe args chdir lfile env = do
  Dirs {..} <- getDirs
  logDebug $ T.pack $ "Running " <> exe <> " with arguments " <> show args
-  let stdoutLogfile = logsDir </> lfile <> ".stdout.log"
-      stderrLogfile = logsDir </> lfile <> ".stderr.log"
+  let stdoutLogfile = fromGHCupPath logsDir </> lfile <> ".stdout.log"
+      stderrLogfile = fromGHCupPath logsDir </> lfile <> ".stderr.log"
  cp <- createProcessWithMingwPath ((proc exe args)
    { cwd = chdir
    , env = env
@@ -199,7 +196,7 @@ execLogged exe args chdir lfile env = do
            -- subprocess stdout also goes to stderr for logging
            void $ BS.hPut stderr some
            go
-        
+

 -- | Thin wrapper around `executeFile`.
 exec :: MonadIO m
@@ -209,10 +206,36 @@ exec :: MonadIO m
     -> Maybe [(String, String)] -- ^ optional environment
     -> m (Either ProcessError ())
 exec exe args chdir env = do
+  -- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/375
+  forM_ (Map.fromList <$> env) $ \cEnv -> do
+    let paths = ["PATH", "Path"]
+        curPaths = (\x -> maybe [] splitSearchPath (Map.lookup x cEnv)) =<< paths
+        newPath = intercalate [searchPathSeparator] curPaths
+    liftIO $ setEnv "PATH" ""
+    liftIO $ setEnv "Path" newPath
  cp <- createProcessWithMingwPath ((proc exe args) { cwd = chdir, env = env })
  exit_code <- liftIO $ withCreateProcess cp $ \_ _ _ p -> waitForProcess p
  pure $ toProcessError exe args exit_code

+-- | Like 'exec', except doesn't add msys2 stuff to PATH.
+execNoMinGW :: MonadIO m
+     => FilePath       -- ^ thing to execute
+     -> [FilePath]     -- ^ args for the thing
+     -> Maybe FilePath   -- ^ optionally chdir into this
+     -> Maybe [(String, String)] -- ^ optional environment
+     -> m (Either ProcessError ())
+execNoMinGW exe args chdir env = do
+  -- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/375
+  forM_ (Map.fromList <$> env) $ \cEnv -> do
+    let paths = ["PATH", "Path"]
+        curPaths = (\x -> maybe [] splitSearchPath (Map.lookup x cEnv)) =<< paths
+        newPath = intercalate [searchPathSeparator] curPaths
+    liftIO $ setEnv "PATH" ""
+    liftIO $ setEnv "Path" newPath
+  let cp = (proc exe args) { cwd = chdir, env = env }
+  exit_code <- liftIO $ withCreateProcess cp $ \_ _ _ p -> waitForProcess p
+  pure $ toProcessError exe args exit_code
+

 -- | Thin wrapper around `executeFile`.
 execShell :: MonadIO m
@@ -228,20 +251,15 @@ execShell exe args chdir env = do
  pure $ toProcessError cmd [] exit_code


-chmod_755 :: MonadIO m => FilePath -> m ()
-chmod_755 fp =
-  let perm = setOwnerWritable True emptyPermissions
-  in liftIO $ setPermissions fp perm
-
-
 createProcessWithMingwPath :: MonadIO m
                          => CreateProcess
                          -> m CreateProcess
 createProcessWithMingwPath cp = do
  msys2Dir <- liftIO ghcupMsys2Dir
  cEnv <- Map.fromList <$> maybe (liftIO getEnvironment) pure (env cp)
-  let mingWPaths = [msys2Dir </> "usr" </> "bin"
-                   ,msys2Dir </> "mingw64" </> "bin"]
+  let mingWPaths = [msys2Dir </> "mingw64" </> "bin"
+                   ,msys2Dir </> "usr" </> "bin"
+                   ]
      paths = ["PATH", "Path"]
      curPaths = (\x -> maybe [] splitSearchPath (Map.lookup x cEnv)) =<< paths
      newPath = intercalate [searchPathSeparator] (mingWPaths ++ curPaths)
@@ -256,16 +274,5 @@ ghcupMsys2Dir =
    Just fp -> pure fp
    Nothing -> do
      baseDir <- liftIO ghcupBaseDir
-      pure (baseDir </> "msys64")
+      pure (fromGHCupPath baseDir </> "msys64")

-- | Checks whether the binary is a broken link.
-isBrokenSymlink :: FilePath -> IO Bool
-isBrokenSymlink fp = do
-  b <- pathIsLink fp
-  if b
-  then do
-    tfp <- getLinkTarget fp
-    not <$> doesPathExist
-      -- this drops 'symDir' if 'tfp' is absolute
-      (takeDirectory fp </> tfp)
-  else pure False
--- a/lib/GHCup/Prelude/String/QQ.hs
+++ b/lib/GHCup/Prelude/String/QQ.hs
@@ -30,7 +30,7 @@ Any instance of the IsString type is permitted.
 (For GHC versions 6, write "[$s||]" instead of "[s||]".)

 -}
-module GHCup.Utils.String.QQ
+module GHCup.Prelude.String.QQ
  ( s
  )
 where
--- a/lib/GHCup/Prelude/Version/QQ.hs
+++ b/lib/GHCup/Prelude/Version/QQ.hs
@@ -16,7 +16,7 @@ Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : portable
 -}
-module GHCup.Utils.Version.QQ where
+module GHCup.Prelude.Version.QQ where

 import           Data.Data
 import           Data.Text                      ( Text )
--- a/lib/GHCup/Prelude/Windows.hs
+++ b/lib/GHCup/Prelude/Windows.hs
@@ -3,7 +3,7 @@
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE OverloadedStrings     #-}

-module GHCup.Utils.Windows where
+module GHCup.Prelude.Windows where


 import           Control.Exception.Safe
@@ -46,3 +46,8 @@ enableAnsiSupport = handleIO (pure . Left . displayException) $ do
    >> pure (Right False)
  else pure (Right True)

+
+isWindows, isNotWindows :: Bool
+isWindows = True
+isNotWindows = not isWindows
+
--- a/lib/GHCup/Prompts.hs
+++ b/lib/GHCup/Prompts.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts #-}
+
+module GHCup.Prompts
+  ( PromptQuestion,
+    PromptResponse (..),
+    getUserPromptResponse,
+  )
+where
+
+import Control.Monad.Reader
+import qualified Data.Text.IO as TIO
+import GHCup.Prelude.Logger
+import GHCup.Types.Optics
+import GHCup.Types (PromptQuestion, PromptResponse(..))
+
+getUserPromptResponse :: ( HasLog env
+                         , MonadReader env m
+                         , MonadIO m)
+                      => PromptQuestion
+                      -> m PromptResponse
+
+getUserPromptResponse prompt = do
+  logInfo prompt
+  resp <- liftIO TIO.getLine
+  if resp `elem` ["YES", "yes", "y", "Y"]
+    then pure PromptYes
+    else pure PromptNo
--- a/lib/GHCup/Stack.hs
+++ b/lib/GHCup/Stack.hs
@@ -0,0 +1,283 @@
+{-# LANGUAGE CPP                   #-}
+{-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleContexts      #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
+
+{-|
+Module      : GHCup.Stack
+Description : GHCup installation functions for Stack
+Copyright   : (c) Julian Ospald, 2020
+License     : LGPL-3.0
+Maintainer  : hasufell@hasufell.de
+Stability   : experimental
+Portability : portable
+-}
+module GHCup.Stack where
+
+import           GHCup.Download
+import           GHCup.Errors
+import           GHCup.Types
+import           GHCup.Types.JSON               ( )
+import           GHCup.Types.Optics
+import           GHCup.Utils
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger
+
+import           Codec.Archive                  ( ArchiveResult )
+import           Control.Applicative
+import           Control.Exception.Safe
+import           Control.Monad
+#if !MIN_VERSION_base(4,13,0)
+import           Control.Monad.Fail             ( MonadFail )
+#endif
+import           Control.Monad.Reader
+import           Control.Monad.Trans.Resource
+                                         hiding ( throwM )
+import           Data.Either
+import           Data.List
+import           Data.Maybe
+import           Data.Versions                hiding ( patch )
+import           Haskus.Utils.Variant.Excepts
+import           Optics
+import           Prelude                 hiding ( abs
+                                                , writeFile
+                                                )
+import           Safe                    hiding ( at )
+import           System.FilePath
+import           System.IO.Error
+
+import qualified Data.Text                     as T
+import Text.PrettyPrint.HughesPJClass (prettyShow)
+
+
+
+    --------------------
+    --[ Installation ]--
+    --------------------
+
+
+-- | Installs stack into @~\/.ghcup\/bin/stack-\<ver\>@ and
+-- creates a default @stack -> stack-x.y.z.q@ symlink for
+-- the latest installed version.
+installStackBin :: ( MonadMask m
+                   , MonadCatch m
+                   , MonadReader env m
+                   , HasDirs env
+                   , HasSettings env
+                   , HasPlatformReq env
+                   , HasGHCupInfo env
+                   , HasLog env
+                   , MonadResource m
+                   , MonadIO m
+                   , MonadUnliftIO m
+                   , MonadFail m
+                   )
+                => Version
+                -> InstallDir
+                -> Bool            -- ^ Force install
+                -> Excepts
+                     '[ AlreadyInstalled
+                      , CopyError
+                      , DigestError
+                      , GPGError
+                      , DownloadFailed
+                      , NoDownload
+                      , NotInstalled
+                      , UnknownArchive
+                      , TarDirDoesNotExist
+                      , ArchiveResult
+                      , FileAlreadyExistsError
+                      ]
+                     m
+                     ()
+installStackBin ver installDir forceInstall = do
+  dlinfo <- liftE $ getDownloadInfo Stack ver
+  installStackBindist dlinfo ver installDir forceInstall
+
+
+-- | Like 'installStackBin', except takes the 'DownloadInfo' as
+-- argument instead of looking it up from 'GHCupDownloads'.
+installStackBindist :: ( MonadMask m
+                       , MonadCatch m
+                       , MonadReader env m
+                       , HasPlatformReq env
+                       , HasDirs env
+                       , HasSettings env
+                       , HasLog env
+                       , MonadResource m
+                       , MonadIO m
+                       , MonadUnliftIO m
+                       , MonadFail m
+                       )
+                    => DownloadInfo
+                    -> Version
+                    -> InstallDir
+                    -> Bool           -- ^ Force install
+                    -> Excepts
+                         '[ AlreadyInstalled
+                          , CopyError
+                          , DigestError
+                          , GPGError
+                          , DownloadFailed
+                          , NoDownload
+                          , NotInstalled
+                          , UnknownArchive
+                          , TarDirDoesNotExist
+                          , ArchiveResult
+                          , FileAlreadyExistsError
+                          ]
+                         m
+                         ()
+installStackBindist dlinfo ver installDir forceInstall = do
+  lift $ logDebug $ "Requested to install stack version " <> prettyVer ver
+
+  PlatformRequest {..} <- lift getPlatformReq
+  Dirs {..} <- lift getDirs
+
+  regularStackInstalled <- lift $ stackInstalled ver
+
+  if
+    | not forceInstall
+    , regularStackInstalled
+    , GHCupInternal <- installDir -> do
+        throwE $ AlreadyInstalled Stack ver
+
+    | forceInstall
+    , regularStackInstalled
+    , GHCupInternal <- installDir -> do
+        lift $ logInfo "Removing the currently installed version of Stack first!"
+        liftE $ rmStackVer ver
+
+    | otherwise -> pure ()
+
+  -- download (or use cached version)
+  dl <- liftE $ downloadCached dlinfo Nothing
+
+  -- unpack
+  tmpUnpack <- lift withGHCupTmpDir
+  liftE $ cleanUpOnError tmpUnpack (unpackToDir (fromGHCupPath tmpUnpack) dl)
+  liftE $ catchWarn $ lEM @_ @'[ProcessError] $ darwinNotarization _rPlatform (fromGHCupPath tmpUnpack)
+
+  -- the subdir of the archive where we do the work
+  workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
+
+  case installDir of
+    IsolateDir isoDir -> do                 -- isolated install
+      lift $ logInfo $ "isolated installing Stack to " <> T.pack isoDir
+      liftE $ installStackUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
+    GHCupInternal -> do                     -- regular install
+      liftE $ installStackUnpacked workdir (GHCupBinDir binDir) ver forceInstall
+
+
+-- | Install an unpacked stack distribution.
+installStackUnpacked :: (MonadReader env m, HasLog env, MonadCatch m, MonadIO m)
+              => GHCupPath      -- ^ Path to the unpacked stack bindist (where the executable resides)
+              -> InstallDirResolved
+              -> Version
+              -> Bool          -- ^ Force install
+              -> Excepts '[CopyError, FileAlreadyExistsError] m ()
+installStackUnpacked path installDir ver forceInstall = do
+  lift $ logInfo "Installing stack"
+  let stackFile = "stack"
+  liftIO $ createDirRecursive' (fromInstallDir installDir)
+  let destFileName = stackFile
+                     <> (case installDir of
+                          IsolateDirResolved _ -> ""
+                          _ -> ("-" <>) .  T.unpack . prettyVer $ ver
+                        )
+                     <> exeExt
+      destPath = fromInstallDir installDir </> destFileName
+
+  copyFileE
+    (fromGHCupPath path </> stackFile <> exeExt)
+    destPath
+    (not forceInstall)
+  lift $ chmod_755 destPath
+
+
+
+    -----------------
+    --[ Set stack ]--
+    -----------------
+
+
+-- | Set the @~\/.ghcup\/bin\/stack@ symlink.
+setStack :: ( MonadMask m
+            , MonadReader env m
+            , HasDirs env
+            , HasLog env
+            , MonadThrow m
+            , MonadFail m
+            , MonadIO m
+            , MonadUnliftIO m
+            )
+         => Version
+         -> Excepts '[NotInstalled] m ()
+setStack ver = do
+  let targetFile = "stack-" <> T.unpack (prettyVer ver) <> exeExt
+
+  -- symlink destination
+  Dirs {..} <- lift getDirs
+
+  whenM (liftIO $ not <$> doesFileExist (binDir </> targetFile))
+    $ throwE
+    $ NotInstalled Stack (GHCTargetVersion Nothing ver)
+
+  let stackbin = binDir </> "stack" <> exeExt
+
+  lift $ createLink targetFile stackbin
+
+  liftIO (isShadowed stackbin) >>= \case
+    Nothing -> pure ()
+    Just pa -> lift $ logWarn $ T.pack $ prettyShow (ToolShadowed Cabal pa stackbin ver)
+
+  pure ()
+
+
+unsetStack :: ( MonadMask m
+              , MonadReader env m
+              , HasDirs env
+              , MonadIO m)
+           => m ()
+unsetStack = do
+  Dirs {..} <- getDirs
+  let stackbin = binDir </> "stack" <> exeExt
+  hideError doesNotExistErrorType $ rmLink stackbin
+
+
+    ----------------
+    --[ Rm stack ]--
+    ----------------
+
+-- | Delete a stack version. Will try to fix the @stack@ symlink
+-- after removal (e.g. setting it to an older version).
+rmStackVer :: ( MonadMask m
+              , MonadReader env m
+              , HasDirs env
+              , MonadThrow m
+              , HasLog env
+              , MonadIO m
+              , MonadFail m
+              , MonadCatch m
+              , MonadUnliftIO m
+              )
+           => Version
+           -> Excepts '[NotInstalled] m ()
+rmStackVer ver = do
+  whenM (lift $ fmap not $ stackInstalled ver) $ throwE (NotInstalled Stack (GHCTargetVersion Nothing ver))
+
+  sSet      <- lift stackSet
+
+  Dirs {..} <- lift getDirs
+
+  let stackFile = "stack-" <> T.unpack (prettyVer ver) <> exeExt
+  lift $ hideError doesNotExistErrorType $ recycleFile (binDir </> stackFile)
+
+  when (Just ver == sSet) $ do
+    sVers <- lift $ fmap rights getInstalledStacks
+    case headMay . reverse . sort $ sVers of
+      Just latestver -> setStack latestver
+      Nothing        -> lift $ rmLink (binDir </> "stack" <> exeExt)
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -26,6 +26,8 @@ module GHCup.Types
  )
  where

+import {-# SOURCE #-} GHCup.Utils.Dirs          ( fromGHCupPath, GHCupPath )
+
 import           Control.DeepSeq                ( NFData, rnf )
 import           Data.Map.Strict                ( Map )
 import           Data.List.NonEmpty             ( NonEmpty (..) )
@@ -405,6 +407,9 @@ data AppState = AppState

 instance NFData AppState

+fromAppState :: AppState -> LeanAppState
+fromAppState AppState {..} = LeanAppState {..}
+
 data LeanAppState = LeanAppState
  { settings :: Settings
  , dirs :: Dirs
@@ -438,12 +443,14 @@ defaultSettings = Settings False defaultMetaCache False Never Curl False GHCupUR
 instance NFData Settings

 data Dirs = Dirs
-  { baseDir  :: FilePath
-  , binDir   :: FilePath
-  , cacheDir :: FilePath
-  , logsDir  :: FilePath
-  , confDir  :: FilePath
-  , recycleDir :: FilePath -- mainly used on windows
+  { baseDir    :: GHCupPath
+  , binDir     :: FilePath
+  , cacheDir   :: GHCupPath
+  , logsDir    :: GHCupPath
+  , confDir    :: GHCupPath
+  , dbDir      :: GHCupPath
+  , recycleDir :: GHCupPath -- mainly used on windows
+  , tmpDir     :: GHCupPath
  }
  deriving (Show, GHC.Generic)

@@ -628,3 +635,29 @@ data CapturedProcess = CapturedProcess
  deriving (Eq, Show)

 makeLenses ''CapturedProcess
+
+
+data InstallDir = IsolateDir FilePath
+                | GHCupInternal
+  deriving (Eq, Show)
+
+data InstallDirResolved = IsolateDirResolved FilePath
+                        | GHCupDir GHCupPath
+                        | GHCupBinDir FilePath
+  deriving (Eq, Show)
+
+fromInstallDir :: InstallDirResolved -> FilePath
+fromInstallDir (IsolateDirResolved fp) = fp
+fromInstallDir (GHCupDir fp) = fromGHCupPath fp
+fromInstallDir (GHCupBinDir fp) = fp
+
+
+isSafeDir :: InstallDirResolved -> Bool
+isSafeDir (IsolateDirResolved _) = False
+isSafeDir (GHCupDir _)           = True
+isSafeDir (GHCupBinDir _)        = False
+
+type PromptQuestion = Text
+
+data PromptResponse = PromptYes | PromptNo
+  deriving (Show, Eq)
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -23,7 +23,7 @@ module GHCup.Types.JSON where

 import           GHCup.Types
 import           GHCup.Types.JSON.Utils
-import           GHCup.Utils.MegaParsec
+import           GHCup.Prelude.MegaParsec

 import           Control.Applicative            ( (<|>) )
 import           Data.Aeson              hiding (Key)
@@ -79,37 +79,6 @@ instance FromJSON Tag where
 instance ToJSON URI where
  toJSON = toJSON . E.decodeUtf8With E.lenientDecode . serializeURIRef'

-instance FromJSON URLSource where
-  parseJSON v =
-        parseGHCupURL v
-    <|> parseOwnSourceLegacy v
-    <|> parseOwnSourceNew1 v
-    <|> parseOwnSourceNew2 v
-    <|> parseOwnSpec v
-    <|> legacyParseAddSource v
-    <|> newParseAddSource v
-   where
-    parseOwnSourceLegacy = withObject "URLSource" $ \o -> do
-      r :: URI <- o .: "OwnSource"
-      pure (OwnSource [Right r])
-    parseOwnSourceNew1 = withObject "URLSource" $ \o -> do
-      r :: [URI] <- o .: "OwnSource"
-      pure (OwnSource (fmap Right r))
-    parseOwnSourceNew2 = withObject "URLSource" $ \o -> do
-      r :: [Either GHCupInfo URI] <- o .: "OwnSource"
-      pure (OwnSource r)
-    parseOwnSpec = withObject "URLSource" $ \o -> do
-      r :: GHCupInfo <- o .: "OwnSpec"
-      pure (OwnSpec r)
-    parseGHCupURL = withObject "URLSource" $ \o -> do
-      _ :: [Value] <- o .: "GHCupURL"
-      pure GHCupURL
-    legacyParseAddSource = withObject "URLSource" $ \o -> do
-      r :: Either GHCupInfo URI <- o .: "AddSource"
-      pure (AddSource [r])
-    newParseAddSource = withObject "URLSource" $ \o -> do
-      r :: [Either GHCupInfo URI] <- o .: "AddSource"
-      pure (AddSource r)

 instance FromJSON URI where
  parseJSON = withText "URL" $ \t ->
@@ -349,7 +318,40 @@ deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''GHCupI
 deriveToJSON defaultOptions { sumEncoding = ObjectWithSingleField } ''URLSource
 deriveJSON defaultOptions { sumEncoding = ObjectWithSingleField } ''Key
 deriveJSON defaultOptions { fieldLabelModifier = \str' -> maybe str' T.unpack . T.stripPrefix (T.pack "k-") . T.pack . kebab $ str' } ''UserKeyBindings
-deriveJSON defaultOptions { fieldLabelModifier = \str' -> maybe str' T.unpack . T.stripPrefix (T.pack "u-") . T.pack . kebab $ str' } ''UserSettings
-
 deriveToJSON defaultOptions { fieldLabelModifier = kebab } ''Settings
 deriveToJSON defaultOptions { fieldLabelModifier = drop 2 . kebab } ''KeyBindings -- move under key-bindings key
+
+instance FromJSON URLSource where
+  parseJSON v =
+        parseGHCupURL v
+    <|> parseOwnSourceLegacy v
+    <|> parseOwnSourceNew1 v
+    <|> parseOwnSourceNew2 v
+    <|> parseOwnSpec v
+    <|> legacyParseAddSource v
+    <|> newParseAddSource v
+   where
+    parseOwnSourceLegacy = withObject "URLSource" $ \o -> do
+      r :: URI <- o .: "OwnSource"
+      pure (OwnSource [Right r])
+    parseOwnSourceNew1 = withObject "URLSource" $ \o -> do
+      r :: [URI] <- o .: "OwnSource"
+      pure (OwnSource (fmap Right r))
+    parseOwnSourceNew2 = withObject "URLSource" $ \o -> do
+      r :: [Either GHCupInfo URI] <- o .: "OwnSource"
+      pure (OwnSource r)
+    parseOwnSpec = withObject "URLSource" $ \o -> do
+      r :: GHCupInfo <- o .: "OwnSpec"
+      pure (OwnSpec r)
+    parseGHCupURL = withObject "URLSource" $ \o -> do
+      _ :: [Value] <- o .: "GHCupURL"
+      pure GHCupURL
+    legacyParseAddSource = withObject "URLSource" $ \o -> do
+      r :: Either GHCupInfo URI <- o .: "AddSource"
+      pure (AddSource [r])
+    newParseAddSource = withObject "URLSource" $ \o -> do
+      r :: [Either GHCupInfo URI] <- o .: "AddSource"
+      pure (AddSource r)
+
+deriveJSON defaultOptions { fieldLabelModifier = \str' -> maybe str' T.unpack . T.stripPrefix (T.pack "u-") . T.pack . kebab $ str' } ''UserSettings
+
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP                   #-}
+{-# LANGUAGE BangPatterns          #-}
 {-# LANGUAGE DataKinds             #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE OverloadedStrings     #-}
@@ -22,18 +23,18 @@ module GHCup.Utils
  ( module GHCup.Utils.Dirs
  , module GHCup.Utils
 #if defined(IS_WINDOWS)
-  , module GHCup.Utils.Windows
+  , module GHCup.Prelude.Windows
 #else
-  , module GHCup.Utils.Posix
+  , module GHCup.Prelude.Posix
 #endif
  )
 where


 #if defined(IS_WINDOWS)
-import GHCup.Utils.Windows
+import GHCup.Prelude.Windows
 #else
-import GHCup.Utils.Posix
+import GHCup.Prelude.Posix
 #endif
 import           GHCup.Download
 import           GHCup.Errors
@@ -41,11 +42,13 @@ import           GHCup.Types
 import           GHCup.Types.Optics
 import           GHCup.Types.JSON               ( )
 import           GHCup.Utils.Dirs
-import           GHCup.Utils.File
-import           GHCup.Utils.Logger
-import           GHCup.Utils.MegaParsec
-import           GHCup.Utils.Prelude
-import           GHCup.Utils.String.QQ
+import           GHCup.Version
+import           GHCup.Prelude
+import           GHCup.Prelude.File
+import           GHCup.Prelude.Logger.Internal
+import           GHCup.Prelude.MegaParsec
+import           GHCup.Prelude.Process
+import           GHCup.Prelude.String.QQ

 import           Codec.Archive           hiding ( Directory )
 import           Control.Applicative
@@ -58,6 +61,7 @@ import           Control.Monad.Reader
 import           Control.Monad.Trans.Resource
                                         hiding ( throwM )
 import           Control.Monad.IO.Unlift        ( MonadUnliftIO( withRunInIO ) )
+import           Data.Char                      ( isHexDigit )
 import           Data.Bifunctor                 ( first )
 import           Data.ByteString                ( ByteString )
 import           Data.Either
@@ -71,10 +75,10 @@ import           GHC.IO.Exception
 import           Haskus.Utils.Variant.Excepts
 import           Optics
 import           Safe
-import           System.Directory      hiding   ( findFiles )
 import           System.FilePath
 import           System.IO.Error
 import           Text.Regex.Posix
+import           Text.PrettyPrint.HughesPJClass (prettyShow)
 import           URI.ByteString

 import qualified Codec.Compression.BZip        as BZip
@@ -86,6 +90,9 @@ import qualified Data.Text                     as T
 import qualified Data.Text.Encoding            as E
 import qualified Text.Megaparsec               as MP
 import qualified Data.List.NonEmpty            as NE
+import qualified Streamly.Prelude              as S
+import Control.DeepSeq (force)
+import GHC.IO (evaluate)


 -- $setup
@@ -96,14 +103,14 @@ import qualified Data.List.NonEmpty            as NE
 -- >>> import System.Directory
 -- >>> import URI.ByteString
 -- >>> import qualified Data.Text as T
-- >>> import GHCup.Utils.Prelude
+-- >>> import GHCup.Prelude
 -- >>> import GHCup.Download
 -- >>> import GHCup.Version
 -- >>> import GHCup.Errors
 -- >>> import GHCup.Types
 -- >>> import GHCup.Types.Optics
 -- >>> import Optics
-- >>> import GHCup.Utils.Version.QQ
+-- >>> import GHCup.Prelude.Version.QQ
 -- >>> import qualified Data.Text.Encoding as E
 -- >>> import Control.Monad.Reader
 -- >>> import Haskus.Utils.Variant.Excepts
@@ -277,14 +284,14 @@ rmPlainHLS = do
 ghcInstalled :: (MonadIO m, MonadReader env m, HasDirs env, MonadThrow m) => GHCTargetVersion -> m Bool
 ghcInstalled ver = do
  ghcdir <- ghcupGHCDir ver
-  liftIO $ doesDirectoryExist ghcdir
+  liftIO $ doesDirectoryExist (fromGHCupPath ghcdir)


 -- | Whether the given GHC version is installed from source.
 ghcSrcInstalled :: (MonadIO m, MonadReader env m, HasDirs env, MonadThrow m) => GHCTargetVersion -> m Bool
 ghcSrcInstalled ver = do
  ghcdir <- ghcupGHCDir ver
-  liftIO $ doesFileExist (ghcdir </> ghcUpSrcBuiltFile)
+  liftIO $ doesFileExist (fromGHCupPath ghcdir </> ghcUpSrcBuiltFile)


 -- | Whether the given GHC version is set as the current.
@@ -327,7 +334,7 @@ ghcSet mtarget = do
 getInstalledGHCs :: (MonadReader env m, HasDirs env, MonadIO m) => m [Either FilePath GHCTargetVersion]
 getInstalledGHCs = do
  ghcdir <- ghcupGHCBaseDir
-  fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ listDirectory ghcdir
+  fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ listDirectory (fromGHCupPath ghcdir)
  forM fs $ \f -> case parseGHCupGHCDir f of
    Right r -> pure $ Right r
    Left  _ -> pure $ Left f
@@ -430,7 +437,7 @@ getInstalledHLSs = do
        Nothing        -> pure $ Left f

  hlsdir <- ghcupHLSBaseDir
-  fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ listDirectory hlsdir
+  fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ listDirectory (fromGHCupPath hlsdir)
  new <- forM fs $ \f -> case parseGHCupHLSDir f of
    Right r -> pure $ Right r
    Left  _ -> pure $ Left f
@@ -515,7 +522,7 @@ hlsInstalled ver = do
 isLegacyHLS :: (MonadIO m, MonadReader env m, HasDirs env, MonadCatch m) => Version -> m Bool
 isLegacyHLS ver = do
  bdir <- ghcupHLSDir ver
-  not <$> liftIO (doesDirectoryExist bdir)
+  not <$> liftIO (doesDirectoryExist $ fromGHCupPath bdir)


 -- Return the currently set hls version, if any.
@@ -616,7 +623,7 @@ hlsInternalServerScripts :: (MonadReader env m, HasDirs env, MonadIO m, MonadThr
                          -> m [FilePath]
 hlsInternalServerScripts ver mghcVer = do
  dir <- ghcupHLSDir ver
-  let bdir = dir </> "bin"
+  let bdir = fromGHCupPath dir </> "bin"
  fmap (bdir </>) . filter (\f -> maybe True (\gv -> ("-" <> T.unpack (prettyVer gv)) `isSuffixOf` f) mghcVer)
    <$> liftIO (listDirectory bdir)

@@ -627,7 +634,7 @@ hlsInternalServerBinaries :: (MonadReader env m, HasDirs env, MonadIO m, MonadTh
                          -> Maybe Version   -- ^ optional GHC version
                          -> m [FilePath]
 hlsInternalServerBinaries ver mghcVer = do
-  dir <- ghcupHLSDir ver
+  dir <- fromGHCupPath <$> ghcupHLSDir ver
  let regex = makeRegexOpts compExtended execBlank ([s|^haskell-language-server-.*$|] :: ByteString)
  (Just bdir) <- fmap headMay $ liftIO $ expandFilePath [Left (dir </> "lib"), Right regex, Left "bin"]
  fmap (bdir </>) . filter (\f -> maybe True (\gv -> ("-" <> T.unpack (prettyVer gv)) `isSuffixOf` f) mghcVer)
@@ -641,7 +648,7 @@ hlsInternalServerLibs :: (MonadReader env m, HasDirs env, MonadIO m, MonadThrow
                      -> Version   -- ^ GHC version
                      -> m [FilePath]
 hlsInternalServerLibs ver ghcVer = do
-  dir <- ghcupHLSDir ver
+  dir <- fromGHCupPath <$> ghcupHLSDir ver
  let regex = makeRegexOpts compExtended execBlank ([s|^haskell-language-server-.*$|] :: ByteString)
  (Just bdir) <- fmap headMay $ liftIO $ expandFilePath [Left (dir </> "lib"), Right regex, Left ("lib" </> T.unpack (prettyVer ghcVer))]
  fmap (bdir </>) <$> liftIO (listDirectory bdir)
@@ -845,21 +852,21 @@ getArchiveFiles av = do


 intoSubdir :: (MonadReader env m, HasLog env, MonadIO m, MonadThrow m, MonadCatch m)
-           => FilePath       -- ^ unpacked tar dir
+           => GHCupPath       -- ^ unpacked tar dir
           -> TarDir         -- ^ how to descend
-           -> Excepts '[TarDirDoesNotExist] m FilePath
+           -> Excepts '[TarDirDoesNotExist] m GHCupPath
 intoSubdir bdir tardir = case tardir of
  RealDir pr -> do
-    whenM (fmap not . liftIO . doesDirectoryExist $ (bdir </> pr))
+    whenM (fmap not . liftIO . doesDirectoryExist $ fromGHCupPath (bdir `appendGHCupPath` pr))
          (throwE $ TarDirDoesNotExist tardir)
-    pure (bdir </> pr)
+    pure (bdir `appendGHCupPath` pr)
  RegexDir r -> do
    let rs = split (`elem` pathSeparators) r
    foldlM
      (\y x ->
-        (handleIO (\_ -> pure []) . liftIO . findFiles y . regex $ x) >>= (\case
+        (handleIO (\_ -> pure []) . liftIO . findFiles (fromGHCupPath y) . regex $ x) >>= (\case
          []      -> throwE $ TarDirDoesNotExist tardir
-          (p : _) -> pure (y </> p)) . sort
+          (p : _) -> pure (y `appendGHCupPath` p)) . sort
      )
      bdir
      rs
@@ -905,7 +912,7 @@ ghcInternalBinDir :: (MonadReader env m, HasDirs env, MonadThrow m, MonadFail m,
                  => GHCTargetVersion
                  -> m FilePath
 ghcInternalBinDir ver = do
-  ghcdir <- ghcupGHCDir ver
+  ghcdir <- fromGHCupPath <$> ghcupGHCDir ver
  pure (ghcdir </> "bin")


@@ -1016,6 +1023,28 @@ applyPatch patch ddir = do
    !? PatchFailed


+applyAnyPatch :: ( MonadReader env m
+                 , HasDirs env
+                 , HasLog env
+                 , HasSettings env
+                 , MonadUnliftIO m
+                 , MonadCatch m
+                 , MonadResource m
+                 , MonadThrow m
+                 , MonadMask m
+                 , MonadIO m)
+              => Maybe (Either FilePath [URI])
+              -> FilePath
+              -> Excepts '[PatchFailed, DownloadFailed, DigestError, GPGError] m ()
+applyAnyPatch Nothing _                   = pure ()
+applyAnyPatch (Just (Left pdir)) workdir  = liftE $ applyPatches pdir workdir
+applyAnyPatch (Just (Right uris)) workdir = do
+  tmpUnpack <- fromGHCupPath <$> lift withGHCupTmpDir
+  forM_ uris $ \uri -> do
+    patch <- liftE $ download uri Nothing Nothing tmpUnpack Nothing False
+    liftE $ applyPatch patch workdir
+
+
 -- | https://gitlab.haskell.org/ghc/ghc/-/issues/17353
 darwinNotarization :: (MonadReader env m, HasDirs env, MonadIO m)
                   => Platform
@@ -1029,6 +1058,8 @@ darwinNotarization Darwin path = exec
 darwinNotarization _ _ = pure $ Right ()


+
+
 getChangeLog :: GHCupDownloads -> Tool -> Either Version Tag -> Maybe URI
 getChangeLog dls tool (Left v') =
  preview (ix tool % ix v' % viChangeLog % _Just) dls
@@ -1039,7 +1070,6 @@ getChangeLog dls tool (Right tag) =
 -- | Execute a build action while potentially cleaning up:
 --
 --   1. the build directory, depending on the KeepDirs setting
--   2. the install destination, depending on whether the build failed
 runBuildAction :: ( MonadReader env m
                  , HasDirs env
                  , HasSettings env
@@ -1050,15 +1080,12 @@ runBuildAction :: ( MonadReader env m
                  , MonadFail m
                  , MonadCatch m
                  )
-               => FilePath        -- ^ build directory (cleaned up depending on Settings)
-               -> Maybe FilePath  -- ^ dir to *always* clean up on exception
+               => GHCupPath        -- ^ build directory (cleaned up depending on Settings)
               -> Excepts e m a
               -> Excepts e m a
-runBuildAction bdir instdir action = do
+runBuildAction bdir action = do
  Settings {..} <- lift getSettings
  let exAction = do
-        forM_ instdir $ \dir ->
-          hideError doesNotExistErrorType $ recyclePathForcibly dir
        when (keepDirs == Never)
          $ rmBDir bdir
  v <-
@@ -1070,7 +1097,8 @@ runBuildAction bdir instdir action = do

 -- | Clean up the given directory if the action fails,
 -- depending on the Settings.
-cleanUpOnError :: ( MonadReader env m
+cleanUpOnError :: forall e m a env .
+                  ( MonadReader env m
                  , HasDirs env
                  , HasSettings env
                  , MonadIO m
@@ -1080,7 +1108,7 @@ cleanUpOnError :: ( MonadReader env m
                  , MonadFail m
                  , MonadCatch m
                  )
-               => FilePath        -- ^ build directory (cleaned up depending on Settings)
+               => GHCupPath        -- ^ build directory (cleaned up depending on Settings)
               -> Excepts e m a
               -> Excepts e m a
 cleanUpOnError bdir action = do
@@ -1089,13 +1117,33 @@ cleanUpOnError bdir action = do
  flip onException (lift exAction) $ onE_ exAction action


+-- | Clean up the given directory if the action fails,
+-- depending on the Settings.
+cleanFinally :: ( MonadReader env m
+                  , HasDirs env
+                  , HasSettings env
+                  , MonadIO m
+                  , MonadMask m
+                  , HasLog env
+                  , MonadUnliftIO m
+                  , MonadFail m
+                  , MonadCatch m
+                  )
+               => GHCupPath        -- ^ build directory (cleaned up depending on Settings)
+               -> Excepts e m a
+               -> Excepts e m a
+cleanFinally bdir action = do
+  Settings {..} <- lift getSettings
+  let exAction = when (keepDirs == Never) $ rmBDir bdir
+  flip finally (lift exAction) $ onE_ exAction action
+

 -- | Remove a build directory, ignoring if it doesn't exist and gracefully
 -- printing other errors without crashing.
-rmBDir :: (MonadReader env m, HasLog env, MonadUnliftIO m, MonadIO m) => FilePath -> m ()
+rmBDir :: (MonadReader env m, HasLog env, MonadUnliftIO m, MonadIO m) => GHCupPath -> m ()
 rmBDir dir = withRunInIO (\run -> run $
           liftIO $ handleIO (\e -> run $ logWarn $
-               "Couldn't remove build dir " <> T.pack dir <> ", error was: " <> T.pack (displayException e))
+               "Couldn't remove build dir " <> T.pack (fromGHCupPath dir) <> ", error was: " <> T.pack (displayException e))
           $ hideError doesNotExistErrorType
           $ rmPathForcibly dir)

@@ -1113,97 +1161,6 @@ getVersionInfo v' tool =
    )


-- | The file extension for executables.
-exeExt :: String
-exeExt
-  | isWindows = ".exe"
-  | otherwise = ""
-
-- | The file extension for executables.
-exeExt' :: ByteString
-exeExt'
-  | isWindows = ".exe"
-  | otherwise = ""
-
-
-
-
-- | On unix, we can use symlinks, so we just get the
-- symbolic link target.
--
-- On windows, we have to emulate symlinks via shims,
-- see 'createLink'.
-getLinkTarget :: FilePath -> IO FilePath
-getLinkTarget fp
-  | isWindows = do
-      content <- readFile (dropExtension fp <.> "shim")
-      [p] <- pure . filter ("path = " `isPrefixOf`) . lines $ content
-      pure $ stripNewline $ dropPrefix "path = " p
-  | otherwise = getSymbolicLinkTarget fp
-
-
-- | Checks whether the path is a link.
-pathIsLink :: FilePath -> IO Bool
-pathIsLink fp
-  | isWindows = doesPathExist (dropExtension fp <.> "shim")
-  | otherwise = pathIsSymbolicLink fp
-
-
-rmLink :: (MonadReader env m, HasDirs env, MonadIO m, MonadMask m) => FilePath -> m ()
-rmLink fp
-  | isWindows = do
-      hideError doesNotExistErrorType . recycleFile $ fp
-      hideError doesNotExistErrorType . recycleFile $ (dropExtension fp <.> "shim")
-  | otherwise = hideError doesNotExistErrorType . recycleFile $ fp
-
-
-- | Creates a symbolic link on unix and a fake symlink on windows for
-- executables, which:
--     1. is a shim exe
--     2. has a corresponding .shim file in the same directory that
--        contains the target
--
-- This overwrites previously existing files.
--
-- On windows, this requires that 'ensureGlobalTools' was run beforehand.
-createLink :: ( MonadMask m
-              , MonadThrow m
-              , HasLog env
-              , MonadIO m
-              , MonadReader env m
-              , HasDirs env
-              , MonadUnliftIO m
-              , MonadFail m
-              )
-           => FilePath      -- ^ path to the target executable
-           -> FilePath      -- ^ path to be created
-           -> m ()
-createLink link exe
-  | isWindows = do
-      dirs <- getDirs
-      let shimGen = cacheDir dirs </> "gs.exe"
-
-      let shim = dropExtension exe <.> "shim"
-          -- For hardlinks, link needs to be absolute.
-          -- If link is relative, it's relative to the target exe.
-          -- Note that (</>) drops lhs when rhs is absolute.
-          fullLink = takeDirectory exe </> link
-          shimContents = "path = " <> fullLink
-
-      logDebug $ "rm -f " <> T.pack exe
-      rmLink exe
-
-      logDebug $ "ln -s " <> T.pack fullLink <> " " <> T.pack exe
-      liftIO $ copyFile shimGen exe
-      liftIO $ writeFile shim shimContents
-  | otherwise = do
-      logDebug $ "rm -f " <> T.pack exe
-      hideError doesNotExistErrorType $ recycleFile exe
-
-      logDebug $ "ln -s " <> T.pack link <> " " <> T.pack exe
-      liftIO $ createFileLink link exe
-
-
 ensureGlobalTools :: ( MonadMask m
                     , MonadThrow m
                     , HasLog env
@@ -1225,8 +1182,8 @@ ensureGlobalTools
      let dl = downloadCached' shimDownload (Just "gs.exe") Nothing
      void $ (\DigestError{} -> do
          lift $ logWarn "Digest doesn't match, redownloading gs.exe..."
-          lift $ logDebug ("rm -f " <> T.pack (cacheDir dirs </> "gs.exe"))
-          lift $ hideError doesNotExistErrorType $ recycleFile (cacheDir dirs </> "gs.exe")
+          lift $ logDebug ("rm -f " <> T.pack (fromGHCupPath (cacheDir dirs) </> "gs.exe"))
+          lift $ hideError doesNotExistErrorType $ recycleFile (fromGHCupPath (cacheDir dirs) </> "gs.exe")
          liftE @'[GPGError, DigestError , DownloadFailed] $ dl
        ) `catchE` liftE @'[GPGError, DigestError , DownloadFailed] dl
  | otherwise = pure ()
@@ -1234,14 +1191,17 @@ ensureGlobalTools

 -- | Ensure ghcup directory structure exists.
 ensureDirectories :: Dirs -> IO ()
-ensureDirectories (Dirs baseDir binDir cacheDir logsDir confDir trashDir) = do
-  createDirRecursive' baseDir
-  createDirRecursive' (baseDir </> "ghc")
+ensureDirectories (Dirs baseDir binDir cacheDir logsDir confDir trashDir dbDir tmpDir) = do
+  createDirRecursive' (fromGHCupPath baseDir)
+  createDirRecursive' (fromGHCupPath baseDir </> "ghc")
+  createDirRecursive' (fromGHCupPath baseDir </> "hls")
  createDirRecursive' binDir
-  createDirRecursive' cacheDir
-  createDirRecursive' logsDir
-  createDirRecursive' confDir
-  createDirRecursive' trashDir
+  createDirRecursive' (fromGHCupPath cacheDir)
+  createDirRecursive' (fromGHCupPath logsDir)
+  createDirRecursive' (fromGHCupPath confDir)
+  createDirRecursive' (fromGHCupPath trashDir)
+  createDirRecursive' (fromGHCupPath dbDir)
+  createDirRecursive' (fromGHCupPath tmpDir)
  pure ()


@@ -1264,10 +1224,88 @@ ghcBinaryName (GHCTargetVersion Nothing  _) = T.unpack ("ghc" <> T.pack exeExt)
 --   3. if it exists and is non-empty -> panic and leave the house
 installDestSanityCheck :: ( MonadIO m
                          , MonadCatch m
+                          , MonadMask m
                          ) =>
-                          FilePath ->
+                          InstallDirResolved ->
                          Excepts '[DirNotEmpty] m ()
-installDestSanityCheck isoDir = do
+installDestSanityCheck (IsolateDirResolved isoDir) = do
  hideErrorDef [doesNotExistErrorType] () $ do
-    contents <- liftIO $ getDirectoryContentsRecursive isoDir
-    unless (null contents) (throwE $ DirNotEmpty isoDir)
+    empty' <- liftIO $ S.null $ getDirectoryContentsRecursiveUnsafe isoDir
+    when (not empty') (throwE $ DirNotEmpty isoDir)
+installDestSanityCheck _ = pure ()
+
+
+-- | Returns 'Nothing' for legacy installs.
+getInstalledFiles :: ( MonadIO m
+                     , MonadCatch m
+                     , MonadReader env m
+                     , HasDirs env
+                     , MonadFail m
+                     )
+                  => Tool
+                  -> GHCTargetVersion
+                  -> m (Maybe [FilePath])
+getInstalledFiles t v' = hideErrorDef [doesNotExistErrorType] Nothing $ do
+  f <- recordedInstallationFile t v'
+  (force -> !c) <- liftIO
+    (readFile f >>= evaluate)
+  pure (Just $ lines c)
+
+
+-- | Warn if the installed and set HLS is not compatible with the installed and
+-- set GHC version.
+warnAboutHlsCompatibility :: ( MonadReader env m
+                             , HasDirs env
+                             , HasLog env
+                             , MonadThrow m
+                             , MonadCatch m
+                             , MonadIO m
+                             )
+                          => m ()
+warnAboutHlsCompatibility = do
+  supportedGHC <- hlsGHCVersions
+  currentGHC   <- fmap _tvVersion <$> ghcSet Nothing
+  currentHLS   <- hlsSet
+
+  case (currentGHC, currentHLS) of
+    (Just gv, Just hv) | gv `notElem` supportedGHC -> do
+      logWarn $
+        "GHC " <> T.pack (prettyShow gv) <> " is not compatible with " <>
+        "Haskell Language Server " <> T.pack (prettyShow hv) <> "." <> "\n" <>
+        "Haskell IDE support may not work until this is fixed." <> "\n" <>
+        "Install a different HLS version, or install and set one of the following GHCs:" <> "\n" <>
+        T.pack (prettyShow supportedGHC)
+
+    _ -> return ()
+
+
+
+    -----------
+    --[ Git ]--
+    -----------
+
+
+
+isCommitHash :: String -> Bool
+isCommitHash str' = let hex = all isHexDigit str'
+                        len = length str'
+                    in hex && len == 40
+
+
+gitOut :: (MonadReader env m, HasLog env, MonadIO m) => [String] -> FilePath -> Excepts '[ProcessError] m T.Text
+gitOut args dir = do
+  CapturedProcess {..} <- lift $ executeOut "git" args (Just dir)
+  case _exitCode of
+    ExitSuccess   -> pure $ T.pack $ stripNewlineEnd $ T.unpack $ decUTF8Safe' _stdOut
+    ExitFailure c -> do
+      let pe = NonZeroExit c "git" args
+      lift $ logDebug $ T.pack (prettyShow pe)
+      throwE pe
+
+processBranches :: T.Text -> [String]
+processBranches str' = let lines'   = lines (T.unpack str')
+                           words'   = fmap words lines'
+                           refs     = catMaybes $ fmap (`atMay` 1) words'
+                           branches = catMaybes $ fmap (stripPrefix "refs/heads/") $ filter (isPrefixOf "refs/heads/") refs
+                       in branches
+
--- a/lib/GHCup/Utils.hs-boot
+++ b/lib/GHCup/Utils.hs-boot
@@ -1,4 +0,0 @@
-module GHCup.Utils where
-
-getLinkTarget :: FilePath -> IO FilePath
-pathIsLink :: FilePath -> IO Bool
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -3,6 +3,7 @@
 {-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE ViewPatterns          #-}
+{-# LANGUAGE QuasiQuotes           #-}

 {-|
 Module      : GHCup.Utils.Dirs
@@ -30,6 +31,74 @@ module GHCup.Utils.Dirs
  , getConfigFilePath
  , useXDG
  , cleanupTrash
+
+  , GHCupPath
+  , appendGHCupPath
+  , fromGHCupPath
+  , createTempGHCupDirectory
+  , getGHCupTmpDirs
+
+  , removeDirectory
+  , removeDirectoryRecursive
+  , removePathForcibly
+
+  -- System.Directory re-exports
+  , createDirectory
+  , createDirectoryIfMissing
+  , renameDirectory
+  , listDirectory
+  , getDirectoryContents
+  , getCurrentDirectory
+  , setCurrentDirectory
+  , withCurrentDirectory
+  , getHomeDirectory
+  , XdgDirectory(..)
+  , getXdgDirectory
+  , XdgDirectoryList(..)
+  , getXdgDirectoryList
+  , getAppUserDataDirectory
+  , getUserDocumentsDirectory
+  , getTemporaryDirectory
+  , removeFile
+  , renameFile
+  , renamePath
+  , getFileSize
+  , canonicalizePath
+  , makeAbsolute
+  , makeRelativeToCurrentDirectory
+  , doesPathExist
+  , doesFileExist
+  , doesDirectoryExist
+  , findExecutable
+  , findExecutables
+  , findExecutablesInDirectories
+  , findFile
+  , findFileWith
+  , findFilesWith
+  , exeExtension
+  , createFileLink
+  , createDirectoryLink
+  , removeDirectoryLink
+  , pathIsSymbolicLink
+  , getSymbolicLinkTarget
+  , Permissions
+  , emptyPermissions
+  , readable
+  , writable
+  , executable
+  , searchable
+  , setOwnerReadable
+  , setOwnerWritable
+  , setOwnerExecutable
+  , setOwnerSearchable
+  , getPermissions
+  , setPermissions
+  , copyPermissions
+  , getAccessTime
+  , getModificationTime
+  , setAccessTime
+  , setModificationTime
+  , isSymbolicLink
  )
 where

@@ -38,35 +107,86 @@ import           GHCup.Errors
 import           GHCup.Types
 import           GHCup.Types.JSON               ( )
 import           GHCup.Types.Optics
-import           GHCup.Utils.MegaParsec
-import           GHCup.Utils.Logger
-import           GHCup.Utils.Prelude
+import           GHCup.Prelude.MegaParsec
+import           GHCup.Prelude.File.Search
+import           GHCup.Prelude.String.QQ
+import           GHCup.Prelude.Logger.Internal (logWarn, logDebug)
+#if defined(IS_WINDOWS)
+import           GHCup.Prelude.Windows ( isWindows )
+#else
+import           GHCup.Prelude.Posix   ( isWindows )
+#endif

+import           Control.DeepSeq (NFData, rnf)
 import           Control.Exception.Safe
 import           Control.Monad
 import           Control.Monad.IO.Unlift
 import           Control.Monad.Reader
 import           Control.Monad.Trans.Resource hiding (throwM)
+import           Data.List
+import           Data.ByteString                ( ByteString )
 import           Data.Bifunctor
 import           Data.Maybe
 import           Data.Versions
 import           GHC.IO.Exception               ( IOErrorType(NoSuchThing) )
 import           Haskus.Utils.Variant.Excepts
 import           Optics
-import           System.Directory                                                
-import           System.DiskSpace                                                
+import           Safe
+import           System.Directory hiding ( removeDirectory
+                                         , removeDirectoryRecursive
+                                         , removePathForcibly
+                                         , findFiles
+                                         )
+import qualified System.Directory              as SD
+
 import           System.Environment
 import           System.FilePath
 import           System.IO.Temp
+import           Text.Regex.Posix

 import qualified Data.ByteString               as BS
 import qualified Data.Text                     as T
 import qualified Data.Yaml.Aeson               as Y
 import qualified Text.Megaparsec               as MP
-import Control.Concurrent (threadDelay)
+import System.IO.Error (ioeGetErrorType)



+    ---------------------------
+    --[ GHCupPath utilities ]--
+    ---------------------------
+
+-- | A 'GHCupPath' is a safe sub-path that can be recursively deleted.
+--
+-- The constructor is not exported.
+newtype GHCupPath = GHCupPath FilePath
+  deriving (Show, Eq, Ord)
+
+instance NFData GHCupPath where
+  rnf (GHCupPath fp) = rnf fp
+
+appendGHCupPath :: GHCupPath -> FilePath -> GHCupPath
+appendGHCupPath (GHCupPath gp) fp = GHCupPath (gp </> fp)
+
+fromGHCupPath :: GHCupPath -> FilePath
+fromGHCupPath (GHCupPath gp) = gp
+
+createTempGHCupDirectory :: GHCupPath -> FilePath -> IO GHCupPath
+createTempGHCupDirectory (GHCupPath gp) d = GHCupPath <$> createTempDirectory gp d
+
+
+getGHCupTmpDirs :: IO [GHCupPath]
+getGHCupTmpDirs = do
+  tmpdir <- fromGHCupPath <$> ghcupTMPDir
+  ghcup_dirs <- handleIO (\_ -> pure []) $ findFiles
+    tmpdir
+    (makeRegexOpts compExtended
+                   execBlank
+                   ([s|^ghcup-.*$|] :: ByteString)
+    )
+  pure (fmap (\p -> GHCupPath (tmpdir </> p)) $ filter (maybe False ("ghcup-" `isPrefixOf`) . lastMay . splitPath) ghcup_dirs)
+
+
    ------------------------------
    --[ GHCup base directories ]--
    ------------------------------
@@ -76,11 +196,11 @@ import Control.Concurrent (threadDelay)
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
 -- then uses 'XDG_DATA_HOME/ghcup' as per xdg spec.
-ghcupBaseDir :: IO FilePath
+ghcupBaseDir :: IO GHCupPath
 ghcupBaseDir
  | isWindows = do
      bdir <- fromMaybe "C:\\" <$> lookupEnv "GHCUP_INSTALL_BASE_PREFIX"
-      pure (bdir </> "ghcup")
+      pure (GHCupPath (bdir </> "ghcup"))
  | otherwise = do
      xdg <- useXDG
      if xdg
@@ -90,19 +210,19 @@ ghcupBaseDir
            Nothing -> do
              home <- liftIO getHomeDirectory
              pure (home </> ".local" </> "share")
-          pure (bdir </> "ghcup")
+          pure (GHCupPath (bdir </> "ghcup"))
        else do
          bdir <- lookupEnv "GHCUP_INSTALL_BASE_PREFIX" >>= \case
            Just r  -> pure r
            Nothing -> liftIO getHomeDirectory
-          pure (bdir </> ".ghcup")
+          pure (GHCupPath (bdir </> ".ghcup"))


 -- | ~/.ghcup by default
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
 -- then uses 'XDG_CONFIG_HOME/ghcup' as per xdg spec.
-ghcupConfigDir :: IO FilePath
+ghcupConfigDir :: IO GHCupPath
 ghcupConfigDir
  | isWindows = ghcupBaseDir
  | otherwise = do
@@ -114,12 +234,12 @@ ghcupConfigDir
            Nothing -> do
              home <- liftIO getHomeDirectory
              pure (home </> ".config")
-          pure (bdir </> "ghcup")
+          pure (GHCupPath (bdir </> "ghcup"))
        else do
          bdir <- lookupEnv "GHCUP_INSTALL_BASE_PREFIX" >>= \case
            Just r  -> pure r
            Nothing -> liftIO getHomeDirectory
-          pure (bdir </> ".ghcup")
+          pure (GHCupPath (bdir </> ".ghcup"))


 -- | If 'GHCUP_USE_XDG_DIRS' is set (to anything),
@@ -127,7 +247,7 @@ ghcupConfigDir
 -- (which, sadly is not strictly xdg spec).
 ghcupBinDir :: IO FilePath
 ghcupBinDir
-  | isWindows = ghcupBaseDir <&> (</> "bin")
+  | isWindows = (fromGHCupPath <$> ghcupBaseDir) <&> (</> "bin")
  | otherwise = do
      xdg <- useXDG
      if xdg
@@ -137,16 +257,16 @@ ghcupBinDir
            Nothing -> do
              home <- liftIO getHomeDirectory
              pure (home </> ".local" </> "bin")
-        else ghcupBaseDir <&> (</> "bin")
+        else (fromGHCupPath <$> ghcupBaseDir) <&> (</> "bin")


 -- | Defaults to '~/.ghcup/cache'.
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
 -- then uses 'XDG_CACHE_HOME/ghcup' as per xdg spec.
-ghcupCacheDir :: IO FilePath
+ghcupCacheDir :: IO GHCupPath
 ghcupCacheDir
-  | isWindows = ghcupBaseDir <&> (</> "cache")
+  | isWindows = ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "cache"))
  | otherwise = do
      xdg <- useXDG
      if xdg
@@ -156,17 +276,17 @@ ghcupCacheDir
            Nothing -> do
              home <- liftIO getHomeDirectory
              pure (home </> ".cache")
-          pure (bdir </> "ghcup")
-        else ghcupBaseDir <&> (</> "cache")
+          pure (GHCupPath (bdir </> "ghcup"))
+        else ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "cache"))


 -- | Defaults to '~/.ghcup/logs'.
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
 -- then uses 'XDG_CACHE_HOME/ghcup/logs' as per xdg spec.
-ghcupLogsDir :: IO FilePath
+ghcupLogsDir :: IO GHCupPath
 ghcupLogsDir
-  | isWindows = ghcupBaseDir <&> (</> "logs")
+  | isWindows = ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "logs"))
  | otherwise = do
      xdg <- useXDG
      if xdg
@@ -176,16 +296,55 @@ ghcupLogsDir
            Nothing -> do
              home <- liftIO getHomeDirectory
              pure (home </> ".cache")
-          pure (bdir </> "ghcup" </> "logs")
-        else ghcupBaseDir <&> (</> "logs")
+          pure (GHCupPath (bdir </> "ghcup" </> "logs"))
+        else ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "logs"))
+
+
+-- | Defaults to '~/.ghcup/db.
+--
+-- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_CACHE_HOME/ghcup/db as per xdg spec.
+ghcupDbDir :: IO GHCupPath
+ghcupDbDir
+  | isWindows = ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "db"))
+  | otherwise = do
+      xdg <- useXDG
+      if xdg
+        then do
+          bdir <- lookupEnv "XDG_CACHE_HOME" >>= \case
+            Just r  -> pure r
+            Nothing -> do
+              home <- liftIO getHomeDirectory
+              pure (home </> ".cache")
+          pure (GHCupPath (bdir </> "ghcup" </> "db"))
+        else ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "db"))


 -- | '~/.ghcup/trash'.
 -- Mainly used on windows to improve file removal operations
-ghcupRecycleDir :: IO FilePath
-ghcupRecycleDir = ghcupBaseDir <&> (</> "trash")
+ghcupRecycleDir :: IO GHCupPath
+ghcupRecycleDir = ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "trash"))


+-- | Defaults to '~/.ghcup/tmp.
+--
+-- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_CACHE_HOME/ghcup/tmp as per xdg spec.
+ghcupTMPDir :: IO GHCupPath
+ghcupTMPDir
+  | isWindows = ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "tmp"))
+  | otherwise = do
+      xdg <- useXDG
+      if xdg
+        then do
+          bdir <- lookupEnv "XDG_CACHE_HOME" >>= \case
+            Just r  -> pure r
+            Nothing -> do
+              home <- liftIO getHomeDirectory
+              pure (home </> ".cache")
+          pure (GHCupPath (bdir </> "ghcup" </> "tmp"))
+        else ghcupBaseDir <&> (\(GHCupPath gp) -> GHCupPath (gp </> "tmp"))
+

 getAllDirs :: IO Dirs
 getAllDirs = do
@@ -195,6 +354,8 @@ getAllDirs = do
  logsDir    <- ghcupLogsDir
  confDir    <- ghcupConfigDir
  recycleDir <- ghcupRecycleDir
+  tmpDir     <- ghcupTMPDir
+  dbDir      <- ghcupDbDir
  pure Dirs { .. }


@@ -206,16 +367,21 @@ getAllDirs = do
 getConfigFilePath :: (MonadIO m) => m FilePath
 getConfigFilePath = do
  confDir <- liftIO ghcupConfigDir
-  pure $ confDir </> "config.yaml"
+  pure $ fromGHCupPath confDir </> "config.yaml"

 ghcupConfigFile :: (MonadIO m)
                => Excepts '[JSONError] m UserSettings
 ghcupConfigFile = do
  filepath <- getConfigFilePath
-  contents <- liftIO $ handleIO' NoSuchThing (\_ -> pure Nothing) $ Just <$> BS.readFile filepath
+  contents <- liftIO $ handleIO (\e -> if NoSuchThing == ioeGetErrorType e then pure Nothing else liftIO $ ioError e) $ Just <$> BS.readFile filepath
  case contents of
      Nothing -> pure defaultUserSettings
-      Just contents' -> lE' JSONDecodeError . first displayException . Y.decodeEither' $ contents'
+      Just contents' -> liftE
+        . veitherToExcepts @_ @'[JSONError]
+        . either (VLeft . V) VRight
+        . first (JSONDecodeError . displayException)
+        . Y.decodeEither'
+        $ contents'


    -------------------------
@@ -224,10 +390,10 @@ ghcupConfigFile = do


 -- | ~/.ghcup/ghc by default.
-ghcupGHCBaseDir :: (MonadReader env m, HasDirs env) => m FilePath
+ghcupGHCBaseDir :: (MonadReader env m, HasDirs env) => m GHCupPath
 ghcupGHCBaseDir = do
  Dirs {..}  <- getDirs
-  pure (baseDir </> "ghc")
+  pure (baseDir `appendGHCupPath` "ghc")


 -- | Gets '~/.ghcup/ghc/<ghcupGHCDir>'.
@@ -236,11 +402,11 @@ ghcupGHCBaseDir = do
 --   * 8.8.4
 ghcupGHCDir :: (MonadReader env m, HasDirs env, MonadThrow m)
            => GHCTargetVersion
-            -> m FilePath
+            -> m GHCupPath
 ghcupGHCDir ver = do
  ghcbasedir <- ghcupGHCBaseDir
  let verdir = T.unpack $ tVerToText ver
-  pure (ghcbasedir </> verdir)
+  pure (ghcbasedir `appendGHCupPath` verdir)


 -- | See 'ghcupToolParser'.
@@ -252,20 +418,27 @@ parseGHCupHLSDir :: MonadThrow m => FilePath -> m Version
 parseGHCupHLSDir (T.pack -> fp) =
  throwEither $ MP.parse version' "" fp

+-- TODO: inlined from GHCup.Prelude
+throwEither :: (Exception a, MonadThrow m) => Either a b -> m b
+throwEither a = case a of
+  Left  e -> throwM e
+  Right r -> pure r
+
 -- | ~/.ghcup/hls by default, for new-style installs.
-ghcupHLSBaseDir :: (MonadReader env m, HasDirs env) => m FilePath
+ghcupHLSBaseDir :: (MonadReader env m, HasDirs env) => m GHCupPath
 ghcupHLSBaseDir = do
  Dirs {..}  <- getDirs
-  pure (baseDir </> "hls")
+  pure (baseDir `appendGHCupPath` "hls")

 -- | Gets '~/.ghcup/hls/<hls-ver>' for new-style installs.
 ghcupHLSDir :: (MonadReader env m, HasDirs env, MonadThrow m)
            => Version
-            -> m FilePath
+            -> m GHCupPath
 ghcupHLSDir ver = do
  basedir <- ghcupHLSBaseDir
  let verdir = T.unpack $ prettyVer ver
-  pure (basedir </> verdir)
+  pure (basedir `appendGHCupPath` verdir)
+

 mkGhcupTmpDir :: ( MonadReader env m
                 , HasDirs env
@@ -275,31 +448,10 @@ mkGhcupTmpDir :: ( MonadReader env m
                 , MonadThrow m
                 , MonadMask m
                 , MonadIO m)
-              => m FilePath
-mkGhcupTmpDir = do
-  tmpdir <- liftIO getCanonicalTemporaryDirectory
-
-  let minSpace = 5000 -- a rough guess, aight?
-  space <- handleIO (\_ -> pure Nothing) $ fmap Just $ liftIO $ getAvailSpace tmpdir
-  when (maybe False (toBytes minSpace >) space) $ do
-    logWarn ("Possibly insufficient disk space on "
-      <> T.pack tmpdir
-      <> ". At least "
-      <> T.pack (show minSpace)
-      <> " MB are recommended, but only "
-      <> toMB (fromJust space)
-      <> " are free. Consider freeing up disk space or setting TMPDIR env variable.")
-    logWarn
-      "...waiting for 10 seconds before continuing anyway, you can still abort..."
-    liftIO $ threadDelay 10000000 -- give the user a sec to intervene
-
-  liftIO $ createTempDirectory tmpdir "ghcup"
- where
-  toBytes mb = mb * 1024 * 1024
-  toMB b = T.pack $ show (truncate' (fromIntegral b / (1024 * 1024) :: Double) 2)
-  truncate' :: Double -> Int -> Double
-  truncate' x n = fromIntegral (floor (x * t) :: Integer) / t
-      where t = 10^n
+              => m GHCupPath
+mkGhcupTmpDir = GHCupPath <$> do
+  Dirs { tmpDir } <- getDirs
+  liftIO $ createTempDirectory (fromGHCupPath tmpDir) "ghcup"


 withGHCupTmpDir :: ( MonadReader env m
@@ -312,15 +464,15 @@ withGHCupTmpDir :: ( MonadReader env m
                   , MonadThrow m
                   , MonadMask m
                   , MonadIO m)
-                => m FilePath
+                => m GHCupPath
 withGHCupTmpDir = snd <$> withRunInIO (\run ->
  run
    $ allocate
        (run mkGhcupTmpDir)
        (\fp ->
            handleIO (\e -> run
-                $ logDebug ("Resource cleanup failed for " <> T.pack fp <> ", error was: " <> T.pack (displayException e)))
-            . rmPathForcibly
+                $ logDebug ("Resource cleanup failed for " <> T.pack (fromGHCupPath fp) <> ", error was: " <> T.pack (displayException e)))
+            . removePathForcibly
            $ fp))


@@ -360,12 +512,28 @@ cleanupTrash :: ( MonadIO m
             => m ()
 cleanupTrash = do
  Dirs { recycleDir } <- getDirs
-  contents <- liftIO $ listDirectory recycleDir
+  contents <- liftIO $ listDirectory (fromGHCupPath recycleDir)
  if null contents
  then pure ()
  else do
-    logWarn ("Removing leftover files in " <> T.pack recycleDir)
+    logWarn ("Removing leftover files in " <> T.pack (fromGHCupPath recycleDir))
    forM_ contents (\fp -> handleIO (\e ->
        logDebug ("Resource cleanup failed for " <> T.pack fp <> ", error was: " <> T.pack (displayException e))
-      ) $ liftIO $ removePathForcibly (recycleDir </> fp))
+      ) $ liftIO $ removePathForcibly (recycleDir `appendGHCupPath` fp))
+
+
+
+-- System.Directory re-exports with GHCupPath
+
+removeDirectory :: GHCupPath -> IO ()
+removeDirectory (GHCupPath fp) = SD.removeDirectory fp
+
+removeDirectoryRecursive :: GHCupPath -> IO ()
+removeDirectoryRecursive (GHCupPath fp) = SD.removeDirectoryRecursive fp
+
+removePathForcibly :: GHCupPath -> IO ()
+removePathForcibly (GHCupPath fp) = SD.removePathForcibly fp
+
+
+

--- a/lib/GHCup/Utils/Dirs.hs-boot
+++ b/lib/GHCup/Utils/Dirs.hs-boot
@@ -0,0 +1,37 @@
+module GHCup.Utils.Dirs
+ ( GHCupPath
+ , appendGHCupPath
+ , fromGHCupPath
+ , createTempGHCupDirectory
+ , removeDirectory
+ , removeDirectoryRecursive
+ , removePathForcibly
+ )
+ where
+
+import Control.DeepSeq (NFData)
+
+
+-- | A 'GHCupPath' is a safe sub-path that can be recursively deleted.
+newtype GHCupPath = GHCupPath FilePath
+
+instance Show GHCupPath where
+
+instance Eq GHCupPath where
+
+instance Ord GHCupPath where
+
+instance NFData GHCupPath where
+
+appendGHCupPath :: GHCupPath -> FilePath -> GHCupPath
+
+fromGHCupPath :: GHCupPath -> FilePath
+
+createTempGHCupDirectory :: GHCupPath -> FilePath -> IO GHCupPath
+
+removeDirectory :: GHCupPath -> IO ()
+
+removeDirectoryRecursive :: GHCupPath -> IO ()
+
+removePathForcibly :: GHCupPath -> IO ()
+
--- a/lib/GHCup/Utils/File.hs
+++ b/lib/GHCup/Utils/File.hs
@@ -1,17 +0,0 @@
-{-# LANGUAGE CPP #-}
-
-module GHCup.Utils.File (
-  module GHCup.Utils.File.Common,
-#if IS_WINDOWS
-  module GHCup.Utils.File.Windows
-#else
-  module GHCup.Utils.File.Posix
-#endif
-) where
-
-import GHCup.Utils.File.Common
-#if IS_WINDOWS
-import GHCup.Utils.File.Windows
-#else
-import GHCup.Utils.File.Posix
-#endif
--- a/lib/GHCup/Utils/File/Common.hs-boot
+++ b/lib/GHCup/Utils/File/Common.hs-boot
@@ -1,5 +0,0 @@
-module GHCup.Utils.File.Common where
-
-import           Text.Regex.Posix
-
-findFiles :: FilePath -> Regex -> IO [FilePath]
--- a/lib/GHCup/Utils/Logger.hs-boot
+++ b/lib/GHCup/Utils/Logger.hs-boot
@@ -1,19 +0,0 @@
-{-# LANGUAGE FlexibleContexts #-}
-{-# LANGUAGE DataKinds        #-}
-
-module GHCup.Utils.Logger where
-
-import           GHCup.Types
-
-import           Control.Monad.IO.Class
-import           Control.Monad.Reader
-import           Data.Text               ( Text )
-import           Optics
-
-logWarn :: ( MonadReader env m
-           , LabelOptic' "loggerConfig" A_Lens env LoggerConfig
-           , MonadIO m
-           )
-        => Text
-        -> m ()
-
--- a/lib/GHCup/Utils/Prelude/Posix.hs
+++ b/lib/GHCup/Utils/Prelude/Posix.hs
@@ -1,20 +0,0 @@
-module GHCup.Utils.Prelude.Posix where
-
-import System.Directory
-import System.Posix.Files
-
-
-isWindows, isNotWindows :: Bool
-isWindows = False
-isNotWindows = not isWindows
-
-
-moveFile :: FilePath -> FilePath -> IO ()
-moveFile = rename
-
-
-moveFilePortable :: FilePath -> FilePath -> IO ()
-moveFilePortable from to = do
-  copyFile from to
-  removeFile from
-  
--- a/lib/GHCup/Utils/Prelude/Windows.hs
+++ b/lib/GHCup/Utils/Prelude/Windows.hs
@@ -1,17 +0,0 @@
-module GHCup.Utils.Prelude.Windows where
-
-import qualified System.Win32.File             as Win32
-
-
-isWindows, isNotWindows :: Bool
-isWindows = True
-isNotWindows = not isWindows
-
-
-moveFile :: FilePath -> FilePath -> IO ()
-moveFile from to = Win32.moveFileEx from (Just to) 0
-
-
-moveFilePortable :: FilePath -> FilePath -> IO ()
-moveFilePortable = Win32.moveFile
-
--- a/lib/GHCup/Version.hs
+++ b/lib/GHCup/Version.hs
@@ -16,12 +16,18 @@ import           GHCup.Types
 import           Paths_ghcup (version)

 import           Data.Version (Version(versionBranch))
-import           Data.Versions hiding (version)
 import           URI.ByteString
 import           URI.ByteString.QQ

 import qualified Data.List.NonEmpty            as NE
 import qualified Data.Text                     as T
+import qualified Data.Versions as V
+import Control.Exception.Safe (MonadThrow)
+import Data.Text (Text)
+import Data.List.NonEmpty (NonEmpty((:|)))
+import Data.List (intersperse)
+import Control.Monad.Catch (throwM)
+import GHCup.Errors (ParseError(..))

 -- | This reflects the API version of the YAML.
 --
@@ -31,22 +37,72 @@ ghcupURL :: URI
 ghcupURL = [uri|https://raw.githubusercontent.com/haskell/ghcup-metadata/master/ghcup-0.0.7.yaml|]

 -- | The current ghcup version.
-ghcUpVer :: PVP
-ghcUpVer = PVP . NE.fromList . fmap fromIntegral $ versionBranch version
+ghcUpVer :: V.PVP
+ghcUpVer = V.PVP . NE.fromList . fmap fromIntegral $ versionBranch version

 -- | ghcup version as numeric string.
 numericVer :: String
-numericVer = T.unpack . prettyPVP $ ghcUpVer
+numericVer = T.unpack . V.prettyPVP $ ghcUpVer

-versionCmp :: Versioning -> VersionCmp -> Bool
+versionCmp :: V.Versioning -> VersionCmp -> Bool
 versionCmp ver1 (VR_gt ver2)   = ver1 > ver2
 versionCmp ver1 (VR_gteq ver2) = ver1 >= ver2
 versionCmp ver1 (VR_lt ver2)   = ver1 < ver2
 versionCmp ver1 (VR_lteq ver2) = ver1 <= ver2
 versionCmp ver1 (VR_eq ver2)   = ver1 == ver2

-versionRange :: Versioning -> VersionRange -> Bool
+versionRange :: V.Versioning -> VersionRange -> Bool
 versionRange ver' (SimpleRange cmps) = and $ fmap (versionCmp ver') cmps
 versionRange ver' (OrRange cmps range) = 
  versionRange ver' (SimpleRange cmps) || versionRange ver' range

+pvpToVersion :: MonadThrow m => V.PVP -> Text -> m V.Version
+pvpToVersion pvp_ rest =
+  either (\_ -> throwM $ ParseError "Couldn't convert PVP to Version") pure . V.version . (<> rest) . V.prettyPVP $ pvp_
+
+-- | Convert a version to a PVP and unparsable rest.
+--
+-- -- prop> \v -> let (Just (pvp', r)) = versionToPVP v in pvpToVersion pvp' r === Just v
+versionToPVP :: MonadThrow m => V.Version -> m (V.PVP, Text)
+versionToPVP (V.Version (Just _) _ _ _) = throwM $ ParseError "Unexpected epoch"
+versionToPVP v = either (\_ -> (, rest v) <$> alternative v) (pure . (, mempty)) . V.pvp . V.prettyVer $ v
+ where
+  alternative :: MonadThrow m => V.Version -> m V.PVP
+  alternative v' = case NE.takeWhile isDigit (V._vChunks v') of
+    [] -> throwM $ ParseError "Couldn't convert Version to PVP"
+    xs -> pure $ pvpFromList (unsafeDigit <$> xs)
+
+  rest :: V.Version -> Text
+  rest (V.Version _ cs pr me) =
+    let chunks = NE.dropWhile isDigit cs
+        ver = intersperse (T.pack ".") . chunksAsT $ chunks
+        me' = maybe [] (\m -> [T.pack "+",m]) me
+        pr' = foldable [] (T.pack "-" :) $ intersperse (T.pack ".") (chunksAsT pr)
+        prefix = case (ver, pr', me') of
+                   (_:_, _, _) -> T.pack "."
+                   _           -> T.pack ""
+    in prefix <> mconcat (ver <> pr' <> me')
+   where
+    chunksAsT :: Functor t => t V.VChunk -> t Text
+    chunksAsT = fmap (foldMap f)
+      where
+        f :: V.VUnit -> Text
+        f (V.Digits i) = T.pack $ show i
+        f (V.Str s)    = s
+
+    foldable :: Foldable f => f b -> (f a -> f b) -> f a -> f b
+    foldable d g f | null f    = d
+                   | otherwise = g f
+
+
+
+  isDigit :: V.VChunk -> Bool
+  isDigit (V.Digits _ :| []) = True
+  isDigit _                = False
+
+  unsafeDigit :: V.VChunk -> Int
+  unsafeDigit (V.Digits x :| []) = fromIntegral x
+  unsafeDigit _ = error "unsafeDigit: wrong input"
+
+pvpFromList :: [Int] -> V.PVP
+pvpFromList = V.PVP . NE.fromList . fmap fromIntegral
--- a/scripts/bootstrap/bootstrap-haskell
+++ b/scripts/bootstrap/bootstrap-haskell
@@ -12,10 +12,12 @@
 #   * BOOTSTRAP_HASKELL_VERBOSE - any nonzero value for more verbose installation
 #   * BOOTSTRAP_HASKELL_GHC_VERSION - the ghc version to install
 #   * BOOTSTRAP_HASKELL_CABAL_VERSION - the cabal version to install
-#   * BOOTSTRAP_HASKELL_INSTALL_STACK - whether to install latest stack
+#   * BOOTSTRAP_HASKELL_INSTALL_NO_STACK - disable installation of stack
+#   * BOOTSTRAP_HASKELL_INSTALL_NO_STACK_HOOK - disable installation stack ghcup hook
 #   * BOOTSTRAP_HASKELL_INSTALL_HLS - whether to install latest hls
 #   * BOOTSTRAP_HASKELL_ADJUST_BASHRC - whether to adjust PATH in bashrc (prepend)
 #   * BOOTSTRAP_HASKELL_ADJUST_CABAL_CONFIG - whether to adjust mingw paths in cabal.config on windows
+#   * BOOTSTRAP_HASKELL_DOWNLOADER - which downloader to use (default: curl)
 #   * GHCUP_BASE_URL - the base url for ghcup binary download (use this to overwrite https://downloads.haskell.org/~ghcup with a mirror)

 # License: LGPL-3.0
@@ -26,10 +28,11 @@

 plat="$(uname -s)"
 arch=$(uname -m)
-ghver="0.1.17.7"
+ghver="0.1.18.0"
 : "${GHCUP_BASE_URL:=https://downloads.haskell.org/~ghcup}"

 export GHCUP_SKIP_UPDATE_CHECK=yes
+: "${BOOTSTRAP_HASKELL_DOWNLOADER:=curl}"

 case "${plat}" in
        MSYS*|MINGW*)
@@ -133,6 +136,19 @@ _eghcup() {
    fi
 }

+ecabal() {
+	edo _ecabal "$@"
+}
+
+_ecabal() {
+    if [ -n "${CABAL_BIN}" ] ; then
+        "${CABAL_BIN}" "$@"
+    else
+        # shellcheck disable=SC2086
+        "${GHCUP_BIN}/cabal" "$@"
+    fi
+}
+
 _done() {
 	echo
 	echo "==============================================================================="
@@ -313,11 +329,35 @@ download_ghcup() {
    esac
    case "${plat}" in
        MSYS*|MINGW*)
-			edo curl -Lf "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+	                # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+                    ;;
+                "wget")
+	                # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
 			edo chmod +x "${GHCUP_BIN}"/ghcup.exe
 			;;
 		*)
-			edo curl -Lf "${_url}" > "${GHCUP_BIN}"/ghcup
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+	                # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup
+                    ;;
+                "wget")
+	                # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
 			edo chmod +x "${GHCUP_BIN}"/ghcup
 			;;
 	esac
@@ -344,6 +384,17 @@ download_ghcup() {

 	# shellcheck disable=SC1090
    edo . "${GHCUP_DIR}"/env
+    case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+        "curl")
+            eghcup config set downloader Curl
+            ;;
+        "wget")
+            eghcup config set downloader Wget
+            ;;
+        *)
+            die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+            ;;
+    esac
    eghcup upgrade
 }

@@ -537,7 +588,7 @@ adjust_cabal_config() {
    else
        cabal_bin="$HOME/AppData/Roaming/cabal/bin"
    fi
-    edo cabal user-config -a "extra-prog-path: $(cygpath -w "$GHCUP_BIN"), $(cygpath -w "$cabal_bin"), $(cygpath -w "$GHCUP_MSYS2"/usr/bin), $(cygpath -w "$GHCUP_MSYS2"/mingw64/bin)" -a "extra-include-dirs: $(cygpath -w "$GHCUP_MSYS2"/mingw64/include)" -a "extra-lib-dirs: $(cygpath -w "$GHCUP_MSYS2"/mingw64/lib)" -f init
+    ecabal user-config -a "extra-prog-path: $(cygpath -w "$GHCUP_BIN"), $(cygpath -w "$cabal_bin"), $(cygpath -w "$GHCUP_MSYS2"/mingw64/bin), $(cygpath -w "$GHCUP_MSYS2"/usr/bin)" -a "extra-include-dirs: $(cygpath -w "$GHCUP_MSYS2"/mingw64/include)" -a "extra-lib-dirs: $(cygpath -w "$GHCUP_MSYS2"/mingw64/lib)" -f init
 }

 ask_cabal_config_init() {
@@ -609,7 +660,7 @@ ask_hls() {
 		warn "Do you want to install haskell-language-server (HLS)?"
 		warn "HLS is a language-server that provides IDE-like functionality"
 		warn "and can integrate with different editors, such as Vim, Emacs, VS Code, Atom, ..."
-		warn "Also see https://github.com/haskell/haskell-language-server/blob/master/README.md"
+		warn "Also see https://haskell-language-server.readthedocs.io/en/stable/"
 		warn ""
 		warn "[Y] Yes  [N] No  [?] Help (default is \"N\")."
 		warn ""
@@ -642,40 +693,44 @@ ask_hls() {
 }

 ask_stack() {
-	if [ -n "${BOOTSTRAP_HASKELL_INSTALL_STACK}" ] ; then
+    if [ -n "${BOOTSTRAP_HASKELL_INSTALL_NO_STACK}" ] ; then
+		return 0
+    elif [ -n "${BOOTSTRAP_HASKELL_INSTALL_NO_STACK_HOOK}" ] ; then
 		return 1
 	fi

 	if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 		echo "-------------------------------------------------------------------------------"

-		warn "Do you want to install stack?"
-		warn "Stack is a haskell build tool similar to cabal that is used by some projects."
-		warn "Also see https://docs.haskellstack.org/"
+		warn "Do you want to enable better integration of stack with GHCup?"
+        warn "This means that stack won't install its own GHC versions, but uses GHCup's."
+        warn "For more information see:"
+        warn "  https://docs.haskellstack.org/en/stable/yaml_configuration/#ghc-installation-customisation-experimental"
+        warn "If you want to keep stacks vanilla behavior, answer 'No'."
 		warn ""
-		warn "[Y] Yes  [N] No  [?] Help (default is \"N\")."
+		warn "[Y] Yes  [N] No  [?] Help (default is \"Y\")."
 		warn ""

 		while true; do
 			read -r stack_answer </dev/tty

 			case $stack_answer in
-				[Yy]*)
+				[Yy]* | "")
+					return 2 ;;
+				[Nn]*)
 					return 1 ;;
-				[Nn]* | "")
-					return 0 ;;
 				*)
 					echo "Possible choices are:"
 					echo
-					echo "Y - Yes, install stack"
-					echo "N - No, don't install anything more (default)"
+                    echo "Y - Yes, enable better integration (default)"
+					echo "N - No, keep stacks vanilla behavior"
 					echo
 					echo "Please make your choice and press ENTER."
 					;;
 			esac
 		done
 	else
-		return 0
+		return 2
 	fi

 	unset stack_answer
@@ -688,11 +743,11 @@ find_shell
 echo
 echo "Welcome to Haskell!"
 echo
-echo "This script will download and install the following binaries:"
+echo "This script can download and install the following binaries:"
 echo "  * ghcup - The Haskell toolchain installer"
 echo "  * ghc   - The Glasgow Haskell Compiler"
 echo "  * cabal - The Cabal build tool for managing Haskell software"
-echo "  * stack - (optional) A cross-platform program for developing Haskell projects"
+echo "  * stack - A cross-platform program for developing Haskell projects (similar to cabal)"
 echo "  * hls   - (optional) A language server for developers to integrate with their editor/IDE"
 echo
 if [ -z "${GHCUP_USE_XDG_DIRS}" ] ; then
@@ -763,7 +818,7 @@ if [ -z "${BOOTSTRAP_HASKELL_MINIMAL}" ] ; then

 	do_cabal_config_init $ask_cabal_config_init_answer

-	edo cabal new-update --ignore-project
+	edo cabal update --ignore-project
 else # don't install ghc and cabal
 	case "${plat}" in
 			MSYS*|MINGW*)
@@ -771,7 +826,7 @@ else # don't install ghc and cabal
 				# we'll remove it afterwards
 				tmp_dir="$(mktemp -d)"
 				eghcup --cache install cabal -i "${tmp_dir}" "${BOOTSTRAP_HASKELL_CABAL_VERSION}"
-				PATH="${tmp_dir}:$PATH" do_cabal_config_init $ask_cabal_config_init_answer
+				CABAL_BIN="${tmp_dir}/cabal" do_cabal_config_init $ask_cabal_config_init_answer
 				rm "${tmp_dir}/cabal"
 				unset tmp_dir
 				;;
@@ -789,7 +844,35 @@ esac

 case $ask_stack_answer in
 	1)
-		_eghcup --cache install stack || warn "Stack installation failed, continuing anyway"
+		_eghcup --cache install stack || die "Stack installation failed"
+		;;
+	2)
+		_eghcup --cache install stack || die "Stack installation failed"
+        edo mkdir -p "${STACK_ROOOT:-$HOME/.stack}"/hooks
+        hook_exe="${STACK_ROOOT:-$HOME/.stack}"/hooks/ghc-install.sh
+        hook_url="https://www.haskell.org/ghcup/sh/hooks/stack/ghc-install.sh"
+
+        if [ -e "${hook_exe}" ] ; then
+            warn "$hook_exe already exists, skipping hook installation."
+            warn "If you want to reinstall the hook, delete it manually and re-run"
+            warn "this script!"
+        else
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+                    # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${hook_url}" > "${hook_exe}"
+                    ;;
+                "wget")
+                    # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${hook_url}" > "${hook_exe}"
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
+            edo chmod +x "${hook_exe}"
+        fi
+
 		;;
 	*) ;;
 esac
--- a/scripts/bootstrap/bootstrap-haskell.ps1
+++ b/scripts/bootstrap/bootstrap-haskell.ps1
@@ -36,7 +36,9 @@ param (
    # Instead of installing a new MSys2, use an existing installation
    [string]$ExistingMsys2Dir,
    # Specify the cabal root directory (default: '$InstallDir\cabal')
-    [string]$CabalDir
+    [string]$CabalDir,
+    # Whether to disable use of curl.exe
+    [switch]$DisableCurl
 )

 $Silent = !$Interactive
@@ -242,7 +244,7 @@ if ($Silent -and !($InstallDir)) {
 	Print-Msg -color Magenta -msg (@'
 Welcome to Haskell!

-This script will download and install the following programs:
+This script can download and install the following programs:
  * ghcup - The Haskell toolchain installer
  * ghc   - The Glasgow Haskell Compiler
  * msys2 - A linux-style toolchain environment required for many operations
@@ -250,7 +252,7 @@ This script will download and install the following programs:
  * stack - (optional) A cross-platform program for developing Haskell projects
  * hls   - (optional) A language server for developers to integrate with their editor/IDE

-Please not that ANTIVIRUS may interfere with the installation. If you experience problems, consider
+Please note that ANTIVIRUS may interfere with the installation. If you experience problems, consider
 disabling it temporarily.

 Where to install to (this should be a short Path, preferably a Drive like 'C:\')?
@@ -425,7 +427,7 @@ if (!(Test-Path -Path ('{0}' -f $MsysDir))) {
    $archive = 'msys2-x86_64-latest.sfx.exe'
    $archivePath = ('{0}\{1}' -f ([IO.Path]::GetTempPath()), "$archive")
    
-    if (Get-Command -Name 'curl.exe' -ErrorAction SilentlyContinue) {
+    if ((Get-Command -Name 'curl.exe' -ErrorAction SilentlyContinue) -and !($DisableCurl)) {
      Exec "curl.exe" '-o' "$archivePath" ('https://repo.msys2.org/distrib/{0}' -f "$archive")
    } else {
      Get-FileWCSynchronous -url ('https://repo.msys2.org/distrib/{0}' -f $archive) -destinationFolder ([IO.Path]::GetTempPath()) -includeStats
@@ -591,10 +593,17 @@ if ($Minimal) {
  $MinimalExport = 'export BOOTSTRAP_HASKELL_MINIMAL=1 ;'
 }

-if ((Get-Process -ID $PID).ProcessName.StartsWith("bootstrap-haskell") -Or $InBash) {
-  Exec "$Bash" '-lc' ('{4} {6} {7} {8} {9} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; [[ ''{0}'' = https* ]]  && curl --proto ''=https'' --tlsv1.2 -sSf {0} | bash || cat $(cygpath -m ''{0}'') | bash' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport)
+if ($DisableCurl) {
+  $BootstrapDownloader = 'export BOOTSTRAP_HASKELL_DOWNLOADER=wget ;'
+  $DownloadScript = 'wget -O /dev/stdout'
 } else {
-  Exec "$Msys2Shell" '-mingw64' '-mintty' '-c' ('{4} {6} {7} {8} {9} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; trap ''echo Press any key to exit && read -n 1 && exit'' 2 ; [[ ''{0}'' = https* ]]  && curl --proto ''=https'' --tlsv1.2 -sSf {0} | bash || cat $(cygpath -m ''{0}'') | bash ; echo ''Press any key to exit'' && read -n 1' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport)
+  $DownloadScript = 'curl --proto ''=https'' --tlsv1.2 -sSf'
+}
+
+if ((Get-Process -ID $PID).ProcessName.StartsWith("bootstrap-haskell") -Or $InBash) {
+  Exec "$Bash" '-lc' ('{4} {6} {7} {8} {9} {10} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; [[ ''{0}'' = https* ]]  && {11} {0} | bash || cat $(cygpath -m ''{0}'') | bash' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport, $BootstrapDownloader, $DownloadScript)
+} else {
+  Exec "$Msys2Shell" '-mingw64' '-mintty' '-c' ('{4} {6} {7} {8} {9} {10} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; trap ''echo Press any key to exit && read -n 1 && exit'' 2 ; [[ ''{0}'' = https* ]]  && {11} {0} | bash || cat $(cygpath -m ''{0}'') | bash ; echo ''Press any key to exit'' && read -n 1' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport, $BootstrapDownloader, $DownloadScript)
 }


--- a/scripts/hooks/stack/ghc-install.sh
+++ b/scripts/hooks/stack/ghc-install.sh
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+# !! KEEP THIS SCRIPT POSIX COMPLIANT !!
+
+# see https://docs.haskellstack.org/en/stable/yaml_configuration/#ghc-installation-customisation-experimental
+# for documentation about hooks
+
+set -eu
+
+case $HOOK_GHC_TYPE in
+    bindist)
+        ghcdir=$(ghcup whereis --directory ghc "$HOOK_GHC_VERSION" || ghcup run --ghc "$HOOK_GHC_VERSION" --install) || exit 3
+        printf "%s/ghc" "${ghcdir}"
+        ;;
+    git)
+        # TODO: should be somewhat possible
+        >&2 echo "Hook doesn't support installing from source"
+        exit 1
+        ;;
+    *)
+        >&2 echo "Unsupported GHC installation type: $HOOK_GHC_TYPE"
+        exit 2
+        ;;
+esac
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,4 @@
-resolver: lts-18.27
+resolver: lts-18.28

 packages:
  - .
@@ -26,7 +26,7 @@ extra-deps:
  - hspec-golden-aeson-0.9.0.0@sha256:aa17274114026661ba4dfc9c60c230673c8f408bd86482fd611d2d5cb6aff996,2179
  - http-io-streams-0.1.6.0@sha256:53f5bab177efb52cd65ec396fd04ed59b93e5f919fb3700cd7dacd6cfce6f06d,3582
  - libarchive-3.0.3.0
-  - libyaml-streamly-0.2.0
+  - libyaml-streamly-0.2.1
  - lzma-static-5.2.5.3@sha256:2758ee58c35992fcf7db78e98684c357a16a82fa2a4e7c352a6c210c08c555d8,7308
  - optics-0.4@sha256:9fb69bf0195b8d8f1f8cd0098000946868b8a3c3ffb51e5b64f79fc600c3eb4c,6568
  - optics-core-0.4@sha256:59e04aebca536bd011ae50c781937f45af4c1456af1eb9fb578f9a69eee293cd,4995
@@ -35,10 +35,11 @@ extra-deps:
  - os-release-1.0.1@sha256:1281c62081f438fc3f0874d3bae6a4887d5964ac25261ba06e29d368ab173467,2716
  - primitive-0.7.1.0@sha256:29de6bfd0cf8ba023ceb806203dfbec0e51e3524e75ffe41056f70b4229c6f0f,2728
  - regex-posix-clib-2.7
-  - streamly-0.8.0@sha256:9784c80ee1ada51477520cabc4e92a0c76a6bb265f968a188f2fce818e7398e0,19654
+  - streamly-0.8.2@sha256:ec521b7c1c4db068501c35804af77f40b7d34232f5e29d9b99e722229040eb80,23500
+  - unicode-data-0.3.0@sha256:0545e079705a5381d0893f8fe8daaa08fc9174baeab269b9cf651817d8eadbc6,5123
  - strict-base-0.4.0.0@sha256:2ff4e43cb95eedf2995558d7fc34d19362846413dd39e6aa6a5b3ea8228fef9f,1248
  - xor-0.0.1.0@sha256:f8362b4a68562b9afbcd727ff64c1a303970df3a032e0033d2f4c094c3501df3,2243
-  - yaml-streamly-0.12.0
+  - yaml-streamly-0.12.1

 flags:
  http-io-streams:
@@ -56,6 +57,9 @@ flags:
  cabal-plan:
    exe: false

+  streamly:
+    use-unliftio: true
+
 ghc-options:
  "$locals": -O2
  streamly: -O2 -fspec-constr-recursive=16 -fmax-worker-args=16
--- a/test/GHCup/Utils/FileSpec.hs
+++ b/test/GHCup/Utils/FileSpec.hs
@@ -0,0 +1,58 @@
+module GHCup.Utils.FileSpec where
+
+import           GHCup.Prelude.File
+
+import           Data.List
+import           System.Directory
+import           System.FilePath
+import           System.IO.Unsafe
+import qualified Streamly.Prelude              as S
+
+import           Test.Hspec
+
+
+
+spec :: Spec
+spec = do
+  describe "GHCup.Utils.File" $ do
+    it "getDirectoryContentsRecursiveBFS" $ do
+      l1 <- sort <$> S.toList (getDirectoryContentsRecursiveBFSUnsafe "lib")
+      l2 <- sort <$> getDirectoryContentsRecursiveLazy "lib"
+      not (null l1) `shouldBe` True
+      not (null l2) `shouldBe` True
+      l1 `shouldBe` l2
+    it "getDirectoryContentsRecursiveDFS" $ do
+      l1 <- sort <$> S.toList (getDirectoryContentsRecursiveDFSUnsafe "lib")
+      l2 <- sort <$> getDirectoryContentsRecursiveLazy "lib"
+      not (null l1) `shouldBe` True
+      not (null l2) `shouldBe` True
+      l1 `shouldBe` l2
+
+
+getDirectoryContentsRecursiveLazy :: FilePath -> IO [FilePath]
+getDirectoryContentsRecursiveLazy topdir = recurseDirectories [""]
+  where
+    recurseDirectories :: [FilePath] -> IO [FilePath]
+    recurseDirectories []         = return []
+    recurseDirectories (dir:dirs) = unsafeInterleaveIO $ do
+      (files, dirs') <- collect [] [] =<< getDirectoryContents (topdir </> dir)
+      files' <- recurseDirectories (dirs' ++ dirs)
+      return (files ++ files')
+
+      where
+        collect files dirs' []              = return (reverse files
+                                                     ,reverse dirs')
+        collect files dirs' (entry:entries) | ignore entry
+                                            = collect files dirs' entries
+        collect files dirs' (entry:entries) = do
+          let dirEntry = dir </> entry
+          isDirectory <- doesDirectoryExist (topdir </> dirEntry)
+          if isDirectory
+            then collect files (dirEntry:dirs') entries
+            else collect (dirEntry:files) dirs' entries
+
+        ignore ['.']      = True
+        ignore ['.', '.'] = True
+        ignore _          = False
+
+
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -1,10 +1,9 @@
 import Test.Hspec.Runner
-import Test.Hspec.Formatters
 import qualified Spec


 main :: IO ()
 main =
  hspecWith
-    defaultConfig { configFormatter = Just progress }
+    defaultConfig
    Spec.spec
Author	SHA1	Message	Date
Julian Ospald	c4912f010d	Switch releases to Github CI	2022-11-09 21:18:21 +08:00
Julian Ospald	787edc17af	Improve stack GHC install script	2022-09-30 13:59:43 +08:00
Julian Ospald	9902adab6d	Make stack GHC install hook posix compliant See https://github.com/commercialhaskell/stack/issues/5888	2022-09-30 13:29:57 +08:00
Julian Ospald	156b4724f3	Merge branch 'stack-hook'	2022-09-26 22:53:40 +08:00
Julian Ospald	e9575aba5c	Add stack ghc installation hooks and install stack by default	2022-09-22 00:04:14 +08:00
Julian Ospald	81c7f6a32a	Merge remote-tracking branch 'origin/merge-requests/283'	2022-08-24 22:34:21 +08:00
taylorfausak	ab97c80b80	Fix build error	2022-08-23 11:59:08 +00:00
taylorfausak	04369673ef	Fix spacing	2022-08-23 11:19:33 +00:00
taylorfausak	63dfdc2da6	Remove hard-coded reference to "cabal" Fixes #407.	2022-08-22 19:35:38 +00:00
Julian Ospald	14de382129	Merge remote-tracking branch 'origin/merge-requests/282'	2022-08-12 22:20:45 +08:00
Julian Ospald	d97c10dbe6	Merge remote-tracking branch 'origin/merge-requests/281'	2022-08-12 22:20:25 +08:00
Cheng Shao	8420bf093e	Update ghc-head bindist URL	2022-08-09 13:32:58 +00:00
amesgen	5e28074522	Account for GHC 9.4.1	2022-08-09 00:43:55 +02:00
Julian Ospald	c842c41a78	Bump to 0.1.18.1 for hackage	2022-08-06 19:11:47 +08:00
Julian Ospald	8b93eaad59	cabal-fmt	2022-08-06 19:08:34 +08:00
Julian Ospald	2cba97cf1c	Merge remote-tracking branch 'origin/merge-requests/277'	2022-08-06 19:07:59 +08:00
Julian Ospald	7d74178295	Merge remote-tracking branch 'origin/merge-requests/279'	2022-08-06 19:07:50 +08:00
Julian Ospald	c37bef55e9	Merge remote-tracking branch 'origin/merge-requests/278'	2022-08-06 19:07:34 +08:00
Julian Ospald	837ba8b46a	Merge remote-tracking branch 'origin/merge-requests/280'	2022-08-06 17:41:09 +08:00
Dmitrii Kovanikov	c25e73408a	Change attribution for the Haskell Beginners 2022 course	2022-08-06 09:33:01 +00:00
why-not-try-calmer	71c3172cf5	Less duplication.	2022-08-05 13:03:02 +02:00
why-not-try-calmer	1f2855a107	Added and referenced solution in case of 'ghc version not found' for Linux VSCode + hls extension users.	2022-08-05 12:51:46 +02:00
Artem Pelenitsyn	d949c4375e	docs: add example of installing bindinst specified by job id	2022-08-05 02:27:35 +00:00
FTS	22f0081303	include c header file in sdict	2022-07-30 16:41:16 +00:00
Julian Ospald	5562be18e3	More docs improvements	2022-07-30 17:18:42 +08:00
Julian Ospald	6baa891424	Update metadata	2022-07-30 10:51:41 +08:00
Julian Ospald	a544feffb3	Finalize release	2022-07-30 10:29:34 +08:00
Julian Ospald	3b6bb0df46	Add changelog	2022-07-29 21:52:56 +08:00
Julian Ospald	60299b6bb8	Update HLS doc link	2022-07-27 23:29:33 +08:00
Julian Ospald	4d20f4e07c	Merge branch 'issue-391'	2022-07-25 20:33:21 +08:00
Julian Ospald	5f6b5f845d	Add --disable-ld-override for darwin bindists Fixes #391	2022-07-25 17:57:10 +08:00
Julian Ospald	b0fecce0d1	Merge remote-tracking branch 'origin/merge-requests/273'	2022-07-24 20:24:00 +08:00
Mike Pilgrem	27c06ddde7	Fix #293 Document expressly how installation scripts can be customised The proposed addition does not go into the mechanism (the names of the specific environment variables or the PowerShell parameters) but is more express about in what manner the behaviour of the installation scripts can be changed. Introduces that important flexibility as the first topic under 'More on installation'. Explains that the PowerShell script finally (by default) runs the script for Unix-like operating systems (so a Windows user understands better that the environment variables in the former are applicable to both, and what is meant by the 'final' bootstrap script in the content of the Windows parameters). Refers to what has gone before, under 'Continuous integration', rather than repeat the added content.	2022-07-23 21:32:15 +01:00
Julian Ospald	3154d2839b	Merge remote-tracking branch 'origin/merge-requests/272'	2022-07-23 23:27:33 +08:00
Mike Pilgrem	511d8d5ed8	Update guide.md to explain what is meant by 'TUI'.	2022-07-23 14:25:49 +00:00
Julian Ospald	fe22405ee1	Merge branch 'issue-383'	2022-07-12 20:44:09 +02:00
Julian Ospald	ea828cd13a	Fix non-interactive install on windows	2022-07-12 20:26:57 +02:00
Julian Ospald	00fa70b9de	Merge remote-tracking branch 'origin/merge-requests/266'	2022-07-12 00:15:14 +02:00
Julian Ospald	823275363c	Merge branch 'ghcup-run-improvements'	2022-07-12 00:10:17 +02:00
Julian Ospald	2f299ee48d	Merge branch 'hls-hackage'	2022-07-12 00:06:40 +02:00
Julian Ospald	284fe1b3b6	Fix parser and completer for 'ghcup compile hls --version'	2022-07-12 00:05:08 +02:00
Julian Ospald	35bda8d67a	Fix hlint warnings	2022-07-11 19:49:08 +02:00
Julian Ospald	7a2a5074fa	Fix parsing issues with 'ghcup run' and non-PVP versions This is a major refactor of some CLI code. We try to distinguish GHC versions from other versions, so that we can use distinct parsers. Hopefully this doesn't introduce new bugs. This also forces ghcup run to use the new internal ~/.ghcup/tmp dir.	2022-07-11 19:45:15 +02:00
Julian Ospald	ce239ab88e	Fix error message	2022-07-11 19:44:10 +02:00
Julian Ospald	f3c703d655	Support hls in 'ghcup changelog'	2022-07-11 19:44:10 +02:00
Julian Ospald	b6ff5bc764	Use ghcup's internal dir for 'ghcup run'	2022-07-11 19:43:48 +02:00
Julian Ospald	b8aeb1f935	Fix guide	2022-07-11 00:43:18 +02:00
Julian Ospald	9673d28d3e	Docs	2022-07-11 00:40:39 +02:00
Julian Ospald	99a51d67a1	Make compiling from hackage the default	2022-07-10 21:58:03 +02:00
Julian Ospald	b0ef0590a2	Merge branch 'pwsh'	2022-07-10 21:21:17 +02:00
Julian Ospald	256e1942f2	More stuff	2022-07-10 21:19:45 +02:00
Julian Ospald	aa71f0dfa1	Set wget	2022-07-10 21:05:51 +02:00
Julian Ospald	04d527c98a	Add DisableCurl powershell switch	2022-07-10 20:58:30 +02:00
Arjun Kathuria	ca5c5550ab	removes newline after set' function	2022-07-10 21:49:54 +05:30
Julian Ospald	7b59621179	Support wget in bootstrap script	2022-07-10 17:56:00 +02:00
Julian Ospald	9d59463ded	Add GHCUP_CURL_OPTS to bootstrap script	2022-07-10 17:35:45 +02:00
Arjun Kathuria	3d49f79beb	removes `prettyShow` from error case in BrickMain set'	2022-07-10 09:52:57 +05:30
Arjun Kathuria	e9740d13fc	Updates `userPrompt` in BrickMain to a more efficient version	2022-07-10 09:50:58 +05:30
Arjun Kathuria	2bd5a8fe1a	Removes redundant `putPrompt` function from Prompts module.	2022-07-10 09:45:39 +05:30
Arjun Kathuria	0acccae523	Removes `GHCup.Types.Prompts` module and stuffs it into `GHCup.Types`	2022-07-10 09:44:23 +05:30
Julian Ospald	974112016e	Allow to run 'cabal update' automatically before the HLS build	2022-07-09 23:50:20 +02:00
Julian Ospald	9fb2889696	Allow to build from arbitrary GHC source dists	2022-07-09 23:12:00 +02:00
Julian Ospald	63f22b28d7	Allow to build HLS from hackage	2022-07-09 21:12:23 +02:00
Julian Ospald	9a72fa13d5	Relax Cabal bounds	2022-07-09 18:04:03 +02:00
Julian Ospald	86a8a32032	Merge branch 'issue-380'	2022-07-07 17:04:42 +02:00
Julian Ospald	13e01ab453	Fix hlint warnings	2022-07-07 15:05:51 +02:00
Julian Ospald	873dd77a6f	Fix build on windows	2022-07-07 15:05:51 +02:00
Julian Ospald	544c618473	Don't remove legacy dir if it doesn't exist	2022-07-07 14:03:49 +02:00
Julian Ospald	a264cb088e	Improve 'ghcup compile hls' 1. short hashes now work 2. print the long hash in addition to the detected cabal version of HLS 3. add `--git-describe-version` switch as an alternative to `--overwrite-version` Fix 1. and 2. for GHC as well.	2022-07-06 22:49:11 +02:00
Julian Ospald	1a43fddca9	Improve about docs	2022-07-02 20:34:19 +02:00
Arjun Kathuria	9ceb66ef21	chore: fix a hlint warning	2022-06-28 22:10:02 +05:30
Arjun Kathuria	7cbe38b011	Behavior Enhancement: make user press "S" only once to set, asks to install AND set if tool uninstalled	2022-06-28 19:50:22 +05:30
Arjun Kathuria	3bbc1edb19	updates user prompt message for "set" uninstalled version in BrickMain	2022-06-28 19:49:00 +05:30
Arjun Kathuria	b8dac2d7cd	Updates the Prompt module to use logInfo instead of putStrLn, makes the prompt look prettier	2022-06-28 19:45:17 +05:30
Julian Ospald	bdfb1a3a9b	Merge remote-tracking branch 'origin/merge-requests/264'	2022-06-26 23:14:36 +02:00
Julian Ospald	9b8b3e8126	Merge remote-tracking branch 'origin/merge-requests/263'	2022-06-26 23:14:10 +02:00
Julian Ospald	d657c17df4	Merge branch 'issue-375'	2022-06-26 23:11:32 +02:00
Arjun Kathuria	0e1fd68d93	when setting an uninstalled tool in tui, asks user to install first	2022-06-25 13:45:07 +05:30
Arjun Kathuria	c7eceb2330	Adds GHCup.Prompt modules and its types to project	2022-06-25 13:44:25 +05:30
why-not-try-calmer	e143c06697	VSCode integration Typo	2022-06-16 11:07:12 +02:00
Jens Petersen	29da21f5dc	bootstrap-haskell: s/will download/can download/ A one word tweak to weaken the language in the initial explanation to make it "less scary": in general ghcup does not always download all of ghcup, ghc, cabal, stack, and hls (unless requested or they are not already installed, etc), but "will download" sounds like the user is has no choice here except to always download everything, which might give them second thoughts about trying this script and hence adopting ghcup. Perhaps the wording could be made further more precise, but at least "can" gives one less anxiety.	2022-06-11 13:06:54 +08:00
Julian Ospald	028696d4be	Merge branch 'issue-377'	2022-06-09 15:29:01 +02:00
Julian Ospald	4022edb12e	Allow passing bindist configure args wrt #377	2022-06-09 14:42:01 +02:00
Julian Ospald	fde5044194	Merge branch 'issue-371'	2022-06-07 18:44:31 +02:00
Julian Ospald	3af1286ab7	Fix ghcup_bootstrap test	2022-06-07 17:49:33 +02:00
Julian Ospald	bcff46d3d4	Fix mingw PATH handling wrt #371	2022-06-07 14:37:23 +02:00
Julian Ospald	d1c72cdff4	Add --mingw-path switch to 'ghcup run'	2022-06-06 23:03:45 +02:00
Julian Ospald	565bb59f45	Fix ghcup_bootstrap test	2022-06-06 23:03:07 +02:00
Julian Ospald	aae3f31c50	Fix bootstrap-haskell picking system cabal	2022-06-06 23:03:07 +02:00
Julian Ospald	0ce9b5d352	Fix test	2022-06-06 23:03:07 +02:00
Julian Ospald	bf0e5b37ca	Test issue #375	2022-06-06 20:22:45 +02:00
Julian Ospald	fe620835be	Fix 'ghcup run' on windows, fixes #375	2022-06-06 20:18:10 +02:00
Julian Ospald	c7dc77e6bc	Refreeze	2022-06-05 17:18:44 +02:00
Julian Ospald	05c72a3de6	Fix build with 9.2.3	2022-06-05 16:55:08 +02:00
Julian Ospald	0653844931	Fix build with ghc-9.0.2	2022-06-04 23:15:06 +02:00
Julian Ospald	7661046bcb	Update GHC version table	2022-05-28 16:44:15 +02:00
Julian Ospald	16888a12d4	Cleanup	2022-05-28 16:44:08 +02:00
Julian Ospald	9f7df33692	Merge branch 'issue-367'	2022-05-24 12:44:57 +02:00
Julian Ospald	b7007aa100	Merge branch 'excepts-refac'	2022-05-24 12:44:39 +02:00
Julian Ospald	03dfd0cba0	Require --isolate to have an absolute directory, fixes #367	2022-05-23 23:50:49 +02:00
Julian Ospald	0e64d1f22f	Improve AlreadyInstalled	2022-05-23 23:49:43 +02:00
Julian Ospald	c7774450bf	Refactor excepts	2022-05-23 23:37:09 +02:00
Julian Ospald	9375255452	Warn on all tools when shadowed	2022-05-23 16:50:23 +02:00
Julian Ospald	b8b3a16589	Update modgraph	2022-05-23 00:00:57 +02:00
Julian Ospald	e1d86c77d0	Merge branch 'issue-364'	2022-05-22 23:39:41 +02:00
Julian Ospald	001d33eabb	Use 'cabal update'	2022-05-22 22:47:40 +02:00
Julian Ospald	2845425099	Restructure modules	2022-05-22 21:11:40 +02:00
Julian Ospald	c56b9ec3ce	Make windows mergeFileTree more robust	2022-05-21 20:51:13 +02:00
Julian Ospald	68c81577a4	Fix HLS install via compile	2022-05-21 15:03:20 +02:00
Julian Ospald	b5fb8772fe	Fix windows	2022-05-21 11:34:57 +02:00
Julian Ospald	5741e069ad	Fix deletion on missing files	2022-05-20 23:29:31 +02:00
Julian Ospald	df89ddcdf5	Use internal tmpdir	2022-05-20 23:19:33 +02:00
Julian Ospald	c9e1261af2	Some fixes	2022-05-20 00:46:50 +02:00
Julian Ospald	d5efc86d85	Preserve mtime when merging filetrees	2022-05-20 00:32:22 +02:00
Julian Ospald	430b655785	Improve error handling for mergeFileTree	2022-05-20 00:15:25 +02:00
Julian Ospald	1cffa358b8	Fix M1 CI	2022-05-19 21:01:48 +02:00
Julian Ospald	ca89112a8e	Fix for darwin M1	2022-05-17 01:55:56 +02:00
Julian Ospald	65f02a5a7a	Fix test	2022-05-16 23:04:49 +02:00
Julian Ospald	9ccf29903e	Add Ben's GPG key	2022-05-16 21:40:02 +02:00
Julian Ospald	e4b8c9748a	Fix oleg url	2022-05-16 18:03:19 +02:00
Julian Ospald	3318c30cee	Fix stack.yaml	2022-05-16 17:38:46 +02:00
Julian Ospald	b9aba98cd5	Fix recursive deletion in `ghcup nuke`	2022-05-16 17:38:05 +02:00
Julian Ospald	55fdc41137	WIP	2022-05-16 11:29:55 +02:00
Julian Ospald	c9790e5823	Use strongly types `GHCupPath` and restrict destructive operations	2022-05-13 21:35:34 +02:00
Julian Ospald	fa924eac15	Fix CI	2022-05-13 17:59:38 +02:00
Julian Ospald	db4e411dfd	Fix darwin binaries after copying	2022-05-13 17:58:15 +02:00
Julian Ospald	48aee1e76c	[WIP] Prototype of recording installed files This also installs makefile based build system via DESTDIR into a temporary directory and then merges it into the filesystem.	2022-05-13 00:46:47 +02:00
Julian Ospald	2a2ace603b	Bump	2022-05-12 18:35:38 +02:00
Julian Ospald	25f9ac71ca	Merge branch 'windows-hotfix'	2022-05-12 18:33:19 +02:00
Julian Ospald	61e2801838	Windows fix	2022-05-12 18:03:04 +02:00
Julian Ospald	e60b8ee238	Merge branch 'CIi'	2022-05-12 17:15:55 +02:00
Julian Ospald	dc0ea5a59c	Document and handle '--force' option better	2022-05-12 13:28:09 +02:00
Julian Ospald	10e704cd73	Fix CI	2022-05-12 13:17:40 +02:00
Julian Ospald	8004cc0537	Make sure root-clenaup runs	2022-05-12 01:12:45 +02:00
Julian Ospald	0a2373f407	Fix CI	2022-05-12 00:17:46 +02:00
Julian Ospald	96f87eaf5f	Update timestamp in CHANGELOG	2022-05-11 23:52:19 +02:00
Julian Ospald	e9bd687b8f	Update ghcup version in bootstrap-haskell	2022-05-11 23:39:45 +02:00
Julian Ospald	3ffa38cf98	Update guide	2022-05-11 23:39:37 +02:00
Julian Ospald	a770c4bcca	Update CHANGELOG	2022-05-11 23:08:26 +02:00
Julian Ospald	f648a6e698	Update submodule	2022-05-11 22:31:06 +02:00
Julian Ospald	a72a12b96d	Test that --isolate --force bevaves well	2022-05-11 22:30:55 +02:00
Julian Ospald	591c54b5f7	Update CHANGELOG	2022-05-11 20:42:48 +02:00
Julian Ospald	a6a54f34cf	Merge branch 'issue-360'	2022-05-11 20:35:56 +02:00
Julian Ospald	f7811961b5	Merge branch 'isolateDir'	2022-05-11 20:35:38 +02:00
Julian Ospald	ee778e1177	Print bindir	2022-05-11 20:13:24 +02:00
Julian Ospald	5787a662ed	Add a --quick switch to 'ghcup run' Also fixes #360, because we resolve all tags/versions now by default.	2022-05-11 20:11:35 +02:00
Julian Ospald	fce654f3c7	Update CHANGELOG	2022-05-11 16:21:37 +02:00
Julian Ospald	0f052c3465	Merge branch 'reenable-upgrade'	2022-05-11 16:20:28 +02:00
Julian Ospald	c733810fdc	Bump version to 0.1.17.8	2022-05-11 16:19:34 +02:00
Julian Ospald	5130cb013b	Fix HLS not cleaning up after failed install, fix #361	2022-05-11 16:18:35 +02:00
Julian Ospald	991e540c11	Refactor code around isolateDirs, so we have proper knowledge	2022-05-11 16:18:35 +02:00
Julian Ospald	a34d9b7b89	Fix type in bootstrap-haskell.ps1	2022-05-09 12:41:54 +02:00
Julian Ospald	4e62f559fa	Update stackage resolver	2022-05-09 12:40:42 +02:00
Julian Ospald	8c3d2b6740	Merge branch 'improve-pwsh'	2022-05-04 16:05:00 +02:00
Julian Ospald	b036c9861f	Re-enable upgrade functionality for all configurations Adds a --fail-if-shadowed switch.	2022-05-04 14:15:17 +02:00