First cross try

Update bash-completion
Fix bug with missing ~/.ghcup/ghc/ dir
2020-04-27 07:49:08 +02:00 · 2020-04-27 07:47:46 +02:00 · 2020-04-26 22:06:00 +02:00 · 2020-04-26 20:17:59 +02:00 · 2020-04-26 11:55:47 +02:00 · 2020-04-25 13:22:12 +02:00
35 changed files with 3984 additions and 567 deletions
--- a/.bash-completion
+++ b/.bash-completion
@@ -0,0 +1,14 @@
+_ghcup()
+{
+    local CMDLINE
+    local IFS=$'\n'
+    CMDLINE=(--bash-completion-index $COMP_CWORD)
+
+    for arg in ${COMP_WORDS[@]}; do
+        CMDLINE=(${CMDLINE[@]} --bash-completion-word $arg)
+    done
+
+    COMPREPLY=( $(ghcup "${CMDLINE[@]}") )
+}
+
+complete -o filenames -F _ghcup ghcup
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,16 +12,52 @@ variables:
  image: "registry.gitlab.haskell.org/ghc/ci-images/x86_64-linux-deb9:$DOCKER_REV"
  tags:
    - x86_64-linux
+  variables:
+    OS: "LINUX"
+
+.alpine:64bit:
+  image: "alpine:edge"
+  tags:
+    - x86_64-linux
+  variables:
+    OS: "LINUX"
+    BIT: "64"
+
+.alpine:32bit:
+  image: "i386/alpine:edge"
+  tags:
+    - x86_64-linux
+  variables:
+    OS: "LINUX"
+    BIT: "32"

 .darwin:
  tags:
    - x86_64-darwin
+  variables:
+    OS: "DARWIN"
+
+.freebsd:
+  tags:
+    - x86_64-freebsd
+  variables:
+    OS: "FREEBSD"
+
+.root_cleanup:
+  after_script:
+    - BUILD_DIR=$CI_PROJECT_DIR
+    - echo "Cleaning $BUILD_DIR"
+    - cd $HOME
+    - test -n "$BUILD_DIR"
+    - shopt -s extglob
+    - rm -Rf "$BUILD_DIR"/!(out)
+    - exit 0

 .test_ghcup_version:
  script:
    - ./.gitlab/script/ghcup_version.sh
  variables:
-    JSON_VERSION: "0.0.1"
+    JSON_VERSION: "0.0.2"

 .test_ghcup_version:linux:
  extends:
@@ -29,50 +65,133 @@ variables:
    - .debian
  before_script:
    - ./.gitlab/before_script/linux/install_deps.sh
-  variables:
-    OS: "LINUX"

 .test_ghcup_version:darwin:
  extends:
    - .test_ghcup_version
    - .darwin
+    - .root_cleanup
  before_script:
    - ./.gitlab/before_script/darwin/install_deps.sh
-  variables:
-    OS: "DARWIN"
-  after_script:
-    - BUILD_DIR=$CI_PROJECT_DIR
-    - echo "Cleaning $BUILD_DIR"
-    - cd $HOME
-    - rm -Rf "$BUILD_DIR"/*
-    - exit 0

+.test_ghcup_version:freebsd:
+  extends:
+    - .test_ghcup_version
+    - .freebsd
+    - .root_cleanup
+  before_script:
+    - ./.gitlab/before_script/freebsd/install_deps.sh

+.release_ghcup:
+  script:
+    - ./.gitlab/script/ghcup_release.sh
+  artifacts:
+    expire_in: 2 week
+    paths:
+      - out
+  only:
+    - tags

-######## linux ########
+######## linux test ########

 test:linux:recommended:
  extends: .test_ghcup_version:linux
  variables:
-    GHC_VERSION: "recommended"
+    GHC_VERSION: "8.6.5"
+    CABAL_VERSION: "3.2.0.0"

 test:linux:latest:
  extends: .test_ghcup_version:linux
  variables:
-    GHC_VERSION: "latest"
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
  allow_failure: true


-######## darwin ########
+######## darwin test ########

 test:mac:recommended:
  extends: .test_ghcup_version:darwin
  variables:
-    GHC_VERSION: "recommended"
+    GHC_VERSION: "8.6.5"
+    CABAL_VERSION: "3.2.0.0"

 test:mac:latest:
  extends: .test_ghcup_version:darwin
  variables:
-    GHC_VERSION: "latest"
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
  allow_failure: true

+
+######## freebsd test ########
+
+test:freebsd:recommended:
+  extends: .test_ghcup_version:freebsd
+  variables:
+    GHC_VERSION: "8.6.5"
+    CABAL_VERSION: "3.2.0.0"
+
+test:freebsd:latest:
+  extends: .test_ghcup_version:freebsd
+  variables:
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
+  allow_failure: true
+
+
+######## linux release ########
+
+release:linux:64bit:
+  extends:
+    - .alpine:64bit
+    - .release_ghcup
+  before_script:
+    - ./.gitlab/before_script/linux/alpine/install_deps.sh
+  variables:
+    ARTIFACT: "x86_64-linux-ghcup"
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
+
+
+release:linux:32bit:
+  extends:
+    - .alpine:32bit
+    - .release_ghcup
+  before_script:
+    - ./.gitlab/before_script/linux/alpine/install_deps.sh
+  variables:
+    ARTIFACT: "x86_64-linux-ghcup"
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
+
+
+######## darwin release ########
+
+release:darwin:
+  extends:
+    - .darwin
+    - .release_ghcup
+    - .root_cleanup
+  before_script:
+    - ./.gitlab/before_script/darwin/install_deps.sh
+  variables:
+    ARTIFACT: "x86_64-apple-darwin-ghcup"
+    GHC_VERSION: "8.8.3"
+    CABAL_VERSION: "3.2.0.0"
+    MACOSX_DEPLOYMENT_TARGET: "10.7"
+
+
+######## freebsd release ########
+
+release:freebsd:
+  extends:
+    - .freebsd
+    - .release_ghcup
+    - .root_cleanup
+  before_script:
+    - ./.gitlab/before_script/freebsd/install_deps.sh
+  variables:
+    ARTIFACT: "x86_64-portbld-freebsd-ghcup"
+    GHC_VERSION: "8.6.5"
+
--- a/.gitlab/before_script/darwin/install_deps.sh
+++ b/.gitlab/before_script/darwin/install_deps.sh
@@ -4,11 +4,11 @@ set -eux

 . "$( cd "$(dirname "$0")" ; pwd -P )/../../ghcup_env"

-curl -sSfL https://gitlab.haskell.org/haskell/ghcup/-/raw/master/ghcup > ./ghcup-legacy
-chmod +x ghcup-legacy
+curl -sSfL https://downloads.haskell.org/~ghcup/x86_64-apple-darwin-ghcup > ./ghcup-bin
+chmod +x ghcup-bin

-./ghcup-legacy install ${GHC_VERSION}
-./ghcup-legacy set ${GHC_VERSION}
-./ghcup-legacy install-cabal
+./ghcup-bin install ${GHC_VERSION}
+./ghcup-bin set ${GHC_VERSION}
+./ghcup-bin install-cabal ${CABAL_VERSION}

 exit 0
--- a/.gitlab/before_script/freebsd/install_deps.sh
+++ b/.gitlab/before_script/freebsd/install_deps.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+set -eux
+
+# pkg install --force --yes --no-repo-update curl gcc gmp gmake ncurses perl5 libffi libiconv
+
+. "$( cd "$(dirname "$0")" ; pwd -P )/../../ghcup_env"
+
+curl -sSfL https://downloads.haskell.org/~ghcup/x86_64-portbld-freebsd-ghcup > ./ghcup-bin
+chmod +x ghcup-bin
+
+mkdir -p "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/bin
+# ./ghcup-bin install ${GHC_VERSION}
+# ./ghcup-bin install-cabal ${CABAL_VERSION}
+# ./ghcup-bin set ${GHC_VERSION}
+
+# install cabal-3.2.0.0
+curl -sSfL -o cabal-install-3.2.0.0-x86_64-portbld-freebsd.tar.xz 'https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-portbld-freebsd.tar.xz&dl=1'
+tar xf cabal-install-3.2.0.0-x86_64-portbld-freebsd.tar.xz
+cp cabal "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
+chmod +x "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
+
+exit 0
--- a/.gitlab/before_script/linux/alpine/install_deps.sh
+++ b/.gitlab/before_script/linux/alpine/install_deps.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+set -eux
+
+. "$( cd "$(dirname "$0")" ; pwd -P )/../../../ghcup_env"
+
+apk add --no-cache \
+	curl \
+	gcc \
+	g++ \
+	gmp-dev \
+	ncurses-dev \
+	libffi-dev \
+	make \
+	xz \
+	tar \
+	perl
+
+ln -s libncurses.so /usr/lib/libtinfo.so
+ln -s libncursesw.so.6 /usr/lib/libtinfow.so.6
+if [ "${BIT}" = "32" ] ; then
+	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.4/i386-linux-ghcup-0.1.4 > ./ghcup-bin
+else
+	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.4/x86_64-linux-ghcup-0.1.4 > ./ghcup-bin
+fi
+chmod +x ghcup-bin
+./ghcup-bin upgrade
+./ghcup-bin install ${GHC_VERSION}
+# ./ghcup-bin install-cabal ${CABAL_VERSION}
+# install cabal-3.2.0.0
+if [ "${BIT}" = "32" ] ; then
+	curl -sSfL -o cabal-install-3.2.0.0-i386-alpine-linux-musl.tar.xz 'https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-i386-alpine-linux-musl.tar.xz&dl=1'
+	tar xf cabal-install-3.2.0.0-i386-alpine-linux-musl.tar.xz
+	cp cabal-install-3.2.0.0-i386-alpine-linux-musl "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
+else
+	curl -sSfL -o cabal-install-3.2.0.0-x86_64-alpine-linux-musl.tar.xz 'https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-alpine-linux-musl.tar.xz&dl=1'
+	tar xf cabal-install-3.2.0.0-x86_64-alpine-linux-musl.tar.xz
+	cp cabal-install-3.2.0.0-x86_64-alpine-linux-musl "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
+fi
+chmod +x "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
+
+
+# utils
+apk add --no-cache \
+	bash
+
+## Package specific
+apk add --no-cache \
+	zlib \
+	zlib-dev \
+	zlib-static \
+	gmp \
+	gmp-dev \
+	openssl-dev \
+	openssl-libs-static \
+	xz \
+	xz-dev
+
+
+
--- a/.gitlab/before_script/linux/install_deps.sh
+++ b/.gitlab/before_script/linux/install_deps.sh
@@ -7,10 +7,10 @@ sudo apt-get install -y libnuma-dev zlib1g-dev libgmp-dev libgmp10 libssl-dev li

 . "$( cd "$(dirname "$0")" ; pwd -P )/../../ghcup_env"

-curl -sSfL https://gitlab.haskell.org/haskell/ghcup/-/raw/master/ghcup > ./ghcup-legacy
-chmod +x ghcup-legacy
+curl -sSfL https://downloads.haskell.org/~ghcup/x86_64-linux-ghcup > ./ghcup-bin
+chmod +x ghcup-bin

-./ghcup-legacy install ${GHC_VERSION}
-./ghcup-legacy set ${GHC_VERSION}
-./ghcup-legacy install-cabal
+./ghcup-bin install ${GHC_VERSION}
+./ghcup-bin set ${GHC_VERSION}
+./ghcup-bin install-cabal ${CABAL_VERSION}

--- a/.gitlab/script/ghcup_release.sh
+++ b/.gitlab/script/ghcup_release.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+
+set -eux
+
+. "$( cd "$(dirname "$0")" ; pwd -P )/../ghcup_env"
+
+mkdir -p "$CI_PROJECT_DIR"/.local/bin
+
+ecabal() {
+	cabal --store-dir="$(pwd)"/.store "$@"
+}
+
+# build
+ecabal update
+
+if [ "${OS}" = "LINUX" ] ; then
+	ecabal build -w ghc-${GHC_VERSION} -fcurl --ghc-options='-split-sections -optl-static'
+else
+	ecabal build -w ghc-${GHC_VERSION} -fcurl
+fi
+
+mkdir out
+cp "$(ecabal new-exec -w ghc-${GHC_VERSION} --verbose=0 --offline sh -- -c 'command -v ghcup')" .
+ver=$(./ghcup --numeric-version)
+cp ghcup out/${ARTIFACT}-${ver}
+
--- a/.gitlab/script/ghcup_version.sh
+++ b/.gitlab/script/ghcup_version.sh
@@ -14,32 +14,44 @@ eghcup() {
 	ghcup -v -c -s file://$(pwd)/ghcup-${JSON_VERSION}.json "$@"
 }

-# build
+
+### build
+
 ecabal update

 if [ "${OS}" = "DARWIN" ] ; then
-	ecabal build -fcurl
+	ecabal build -w ghc-${GHC_VERSION} -fcurl
 else
-	ecabal build
+	ecabal build -w ghc-${GHC_VERSION}
 fi

 cp "$(ecabal new-exec --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup')" .
 cp "$(ecabal new-exec --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup-gen')" .

-
-# testing
-
 cp ./ghcup "$CI_PROJECT_DIR"/.local/bin/ghcup
 cp ./ghcup-gen "$CI_PROJECT_DIR"/.local/bin/ghcup-gen
+
+### cleanup
+
 rm -rf "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup

+
+### manual cli based testing
+
+
 ghcup-gen check -f ghcup-${JSON_VERSION}.json

-eghcup numeric-version
+eghcup --numeric-version
+
+# TODO: rm once we have tarballs
+if [ "${OS}"  = "FREEBSD" ] ; then
+	GHC_VERSION=8.6.3
+	CABAL_VERSION=2.4.1.0
+fi

 eghcup install ${GHC_VERSION}
 eghcup set ${GHC_VERSION}
-eghcup install-cabal
+eghcup install-cabal ${CABAL_VERSION}

 cabal --version

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # Revision history for ghcup

-## 0.1.4 -- 2012-04-16
+## 0.1.4 -- 2020-04-16

 * build on all platforms with curl (as a binary), wrt https://gitlab.haskell.org/haskell/ghcup-hs/issues/6
 * Fix unlinking of ghc symlinks after new installation, wrt https://gitlab.haskell.org/haskell/ghcup-hs/issues/7
--- a/README.md
+++ b/README.md
@@ -68,6 +68,12 @@ handles your haskell packages and can demand that [a specific version](https://c
 For man pages to work you need [man-db](http://man-db.nongnu.org/) as your `man` provider, then issue `man ghc`. Manpages only work for the currently set ghc.
 `MANPATH` may be required to be unset.

+### Bash-completion
+
+Depending on your distro and setup, install `.bash-completion` from this repo
+as e.g. `/etc/bash_completion.d/ghcup` and make sure your bashrc sources the
+startup script (`/usr/share/bash-completion/bash_completion` on some distros).
+
 ## Design goals

 1. simplicity
@@ -142,3 +148,6 @@ ghcup is not a reimplementation of stack. The only common part is automatic inst

 Consider using [Chocolatey](https://chocolatey.org/search?q=ghc) or [ghcups](https://github.com/kakkun61/ghcups).

+3. Why the haskell reimplementation?
+
+Why not?
--- a/TODO.md
+++ b/TODO.md
@@ -2,27 +2,39 @@

 ## Now

-* move out GHCup.Version module, bc it's not library-ish
+* try to run exe before upgrade (backup to ~/.ghcup/bin/ghcup.old)
+* allow to build 8.8
+* curl DL does not cache json
+* explain environment variables
+* add --keep=<always|error> option
+
+* allow to switch to curl/wget at runtime
+
+* cross support
+* installing multiple versions of the same
+
+* proper test suite
+* add more logging
+

 ## Maybe

-* maybe: changelog          Show the changelog of a GHC release (online)
+* version ranges in json
 * sign the JSON? (Or check gpg keys?)
 * testing (especially distro detection -> unit tests)

 ## Later

-* i386 support
 * add support for RC/alpha/HEAD versions

 ## Cleanups

-* too many decodeutf8
 * avoid alternative for IO
 * use plucky or oops instead of Excepts

 ## Questions

+* move out GHCup.Version module, bc it's not library-ish?
 * mirror support
 * interactive handling when distro doesn't exist and we know the tarball is incompatible?
 * ghcup-with wrapper to execute a command with a given ghc in PATH?
--- a/app/ghcup-gen/Main.hs
+++ b/app/ghcup-gen/Main.hs
@@ -10,10 +10,10 @@

 module Main where

+import           GHCup.Data.GHCupInfo
 import           GHCup.Types
 import           GHCup.Types.JSON               ( )
 import           GHCup.Utils.Logger
-import           GHCupInfo

 import           Data.Aeson                     ( eitherDecode, encode )
 import           Data.Aeson.Encode.Pretty
--- a/app/ghcup-gen/Validate.hs
+++ b/app/ghcup-gen/Validate.hs
@@ -27,9 +27,12 @@ import           Haskus.Utils.Variant.Excepts
 import           Optics
 import           System.Exit
 import           System.IO
+import           Text.ParserCombinators.ReadP

 import qualified Data.ByteString               as B
 import qualified Data.Map.Strict               as M
+import qualified Data.Text                     as T
+import qualified Data.Version                  as V


 data ValidationError = InternalError String
@@ -61,8 +64,9 @@ validate dls = do
        forM_ (M.toList $ _viArch vi) $ \(arch, pspecs) -> do
          checkHasRequiredPlatforms t v arch (M.keys pspecs)

-    checkGHCisSemver
+    checkGHCVerIsValid
    forM_ (M.toList dls) $ \(t, _) -> checkMandatoryTags t
+    _ <- checkGHCHasBaseVersion

    -- exit
    e <- liftIO $ readIORef ref
@@ -85,7 +89,7 @@ validate dls = do
      [i|FreeBSD missing for #{t} #{v'} #{arch}|]

  checkUniqueTags tool = do
-    let allTags = join $ fmap snd $ availableToolVersions dls tool
+    let allTags = join $ M.elems $ availableToolVersions dls tool
    let nonUnique =
          fmap fst
            .   filter (\(_, b) -> not b)
@@ -105,26 +109,40 @@ validate dls = do
        lift $ $(logError) [i|Tags not unique for #{tool}: #{xs}|]
        addError
   where
-    isUniqueTag Latest      = True
-    isUniqueTag Recommended = True
+    isUniqueTag Latest         = True
+    isUniqueTag Recommended    = True
+    isUniqueTag (Base       _) = False
+    isUniqueTag (UnknownTag _) = False

-  checkGHCisSemver = do
+  checkGHCVerIsValid = do
    let ghcVers = toListOf (ix GHC % to M.keys % folded) dls
-    forM_ ghcVers $ \v -> case semver (prettyVer v) of
-      Left _ -> do
-        lift $ $(logError) [i|GHC version #{v} is not valid semver|]
-        addError
-      Right _ -> pure ()
+    forM_ ghcVers $ \v ->
+      case [ x | (x,"") <- readP_to_S V.parseVersion (T.unpack . prettyVer $ v) ] of
+        [_] -> pure ()
+        _   -> do
+          lift $ $(logError) [i|GHC version #{v} is not valid |]
+          addError

  -- a tool must have at least one of each mandatory tags
  checkMandatoryTags tool = do
-    let allTags = join $ fmap snd $ availableToolVersions dls tool
+    let allTags = join $ M.elems $ availableToolVersions dls tool
    forM_ [Latest, Recommended] $ \t -> case elem t allTags of
      False -> do
        lift $ $(logError) [i|Tag #{t} missing from #{tool}|]
        addError
      True -> pure ()

+  -- all GHC versions must have a base tag
+  checkGHCHasBaseVersion = do
+    let allTags = M.toList $ availableToolVersions dls GHC
+    forM allTags $ \(ver, tags) -> case any isBase tags of
+      False -> do
+        lift $ $(logError) [i|Base tag missing from GHC ver #{ver}|]
+        addError
+      True -> pure ()
+
+  isBase (Base _) = True
+  isBase _        = False

 validateTarballs :: ( Monad m
                    , MonadLogger m
@@ -161,7 +179,7 @@ validateTarballs dls = do

 where
  downloadAll dli = do
-    let settings = Settings True False
+    let settings = Settings True False Never
    let runLogger = myLoggerT LoggerConfig { lcPrintDebug = True
                                           , colorOutter  = B.hPut stderr
                                           , rawOutter    = (\_ -> pure ())
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
--- a/8
+++ b/8
@@ -31,10 +31,10 @@ download_ghcup() {
        "linux"|"Linux")
 			case "${_arch}" in
 				x86_64|amd64)
-					_url=https://downloads.haskell.org/~ghcup/0.1.3/x86_64-linux-ghcup-0.1.3
+					_url=https://downloads.haskell.org/~ghcup/0.1.4/x86_64-linux-ghcup-0.1.4
 					;;
 				i*86)
-					_url=https://downloads.haskell.org/~ghcup/0.1.3/i386-linux-ghcup-0.1.3
+					_url=https://downloads.haskell.org/~ghcup/0.1.4/i386-linux-ghcup-0.1.4
 					;;
 				*) die "Unknown architecture: ${_arch}"
 					;;
@@ -50,7 +50,7 @@ download_ghcup() {
 				*) die "Unknown architecture: ${_arch}"
 					;;
 			esac
-			_url=https://downloads.haskell.org/~ghcup/0.1.3/x86_64-portbld-freebsd-ghcup-0.1.3
+			_url=https://downloads.haskell.org/~ghcup/0.1.4/x86_64-portbld-freebsd-ghcup-0.1.4
            ;;
        "Darwin"|"darwin")
 			case "${_arch}" in
@@ -62,7 +62,7 @@ download_ghcup() {
 				*) die "Unknown architecture: ${_arch}"
 					;;
 			esac
-			_url=https://downloads.haskell.org/~ghcup/0.1.3/x86_64-apple-darwin-ghcup-0.1.3 ;;
+			_url=https://downloads.haskell.org/~ghcup/0.1.4/x86_64-apple-darwin-ghcup-0.1.4 ;;
        *) die "Unknown platform: ${_plat}"
 			;;
    esac
--- a/ghcup-0.0.1.json
+++ b/ghcup-0.0.1.json
@@ -170,6 +170,7 @@
          "dlSubdir": "ghc-8.6.2",
          "dlUri": "https://downloads.haskell.org/~ghc/8.6.2/ghc-8.6.2-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.6.2/docs/html/users_guide/8.6.2-notes.html",
        "viTags": []
      },
      "8.0.2": {
@@ -264,6 +265,7 @@
          "dlSubdir": "ghc-8.0.2",
          "dlUri": "https://downloads.haskell.org/~ghc/8.0.2/ghc-8.0.2-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.0.2/docs/html/users_guide/8.0.1-notes.html",
        "viTags": []
      },
      "8.6.4": {
@@ -377,6 +379,7 @@
          "dlSubdir": "ghc-8.6.4",
          "dlUri": "https://downloads.haskell.org/~ghc/8.6.4/ghc-8.6.4-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.6.4/docs/html/users_guide/8.6.4-notes.html",
        "viTags": []
      },
      "8.4.1": {
@@ -482,6 +485,7 @@
          "dlSubdir": "ghc-8.4.1",
          "dlUri": "https://downloads.haskell.org/~ghc/8.4.1/ghc-8.4.1-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.4.1/docs/html/users_guide/8.4.1-notes.html",
        "viTags": []
      },
      "8.6.3": {
@@ -616,6 +620,7 @@
          "dlSubdir": "ghc-8.6.3",
          "dlUri": "https://downloads.haskell.org/~ghc/8.6.3/ghc-8.6.3-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.6.3/docs/html/users_guide/8.6.3-notes.html",
        "viTags": []
      },
      "8.10.1": {
@@ -756,6 +761,7 @@
          "dlSubdir": "ghc-8.10.1",
          "dlUri": "https://downloads.haskell.org/~ghc/8.10.1/ghc-8.10.1-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.10.1/docs/html/users_guide/8.10.1-notes.html",
        "viTags": [
          "Latest"
        ]
@@ -885,6 +891,7 @@
          "dlSubdir": "ghc-8.6.5",
          "dlUri": "https://downloads.haskell.org/~ghc/8.6.5/ghc-8.6.5-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.6.5/docs/html/users_guide/8.6.5-notes.html",
        "viTags": []
      },
      "8.4.2": {
@@ -1005,6 +1012,7 @@
          "dlSubdir": "ghc-8.4.2",
          "dlUri": "https://downloads.haskell.org/~ghc/8.4.2/ghc-8.4.2-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.4.2/docs/html/users_guide/8.4.2-notes.html",
        "viTags": []
      },
      "8.8.1": {
@@ -1132,6 +1140,7 @@
          "dlSubdir": "ghc-8.8.1",
          "dlUri": "https://downloads.haskell.org/~ghc/8.8.1/ghc-8.8.1-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.8.1/docs/html/users_guide/8.8.1-notes.html",
        "viTags": []
      },
      "8.4.3": {
@@ -1245,6 +1254,7 @@
          "dlSubdir": "ghc-8.4.3",
          "dlUri": "https://downloads.haskell.org/~ghc/8.4.3/ghc-8.4.3-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.4.3/docs/html/users_guide/8.4.3-notes.html",
        "viTags": []
      },
      "8.6.1": {
@@ -1365,6 +1375,7 @@
          "dlSubdir": "ghc-8.6.1",
          "dlUri": "https://downloads.haskell.org/~ghc/8.6.1/ghc-8.6.1-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.6.1/docs/html/users_guide/8.6.1-notes.html",
        "viTags": []
      },
      "8.8.2": {
@@ -1492,6 +1503,7 @@
          "dlSubdir": "ghc-8.8.2",
          "dlUri": "https://downloads.haskell.org/~ghc/8.8.2/ghc-8.8.2-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.8.2/docs/html/users_guide/8.8.2-notes.html",
        "viTags": []
      },
      "7.10.3": {
@@ -1618,6 +1630,7 @@
          "dlSubdir": "ghc-7.10.3",
          "dlUri": "https://downloads.haskell.org/~ghc/7.10.3/ghc-7.10.3-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/7.10.3/docs/html/users_guide/release-7-10-1.html",
        "viTags": []
      },
      "8.2.2": {
@@ -1722,6 +1735,7 @@
          "dlSubdir": "ghc-8.2.2",
          "dlUri": "https://downloads.haskell.org/~ghc/8.2.2/ghc-8.2.2-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.2.2/docs/html/users_guide/8.2.2-notes.html",
        "viTags": []
      },
      "8.4.4": {
@@ -1856,6 +1870,7 @@
          "dlSubdir": "ghc-8.4.4",
          "dlUri": "https://downloads.haskell.org/~ghc/8.4.4/ghc-8.4.4-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.4.4/docs/html/users_guide/8.4.4-notes.html",
        "viTags": []
      },
      "8.8.3": {
@@ -1943,7 +1958,7 @@
          "A_32": {
            "Linux_Alpine": {
              "unknown_versioning": {
-                "dlHash": "23779adb4cf4b314d0f8c66ee215ba6e74154c0768a573780475943544020bec",
+                "dlHash": "7a5f41646d06777e75636291a1855d60a0984552bbdf33c3d107565d302f38a4",
                "dlSubdir": "ghc-8.8.3",
                "dlUri": "https://github.com/redneb/ghc-alt-libc/releases/download/ghc-8.8.3-musl/ghc-8.8.3-i386-unknown-linux-musl.tar.xz"
              }
@@ -1983,6 +1998,7 @@
          "dlSubdir": "ghc-8.8.3",
          "dlUri": "https://downloads.haskell.org/~ghc/8.8.3/ghc-8.8.3-src.tar.xz"
        },
+        "viChangeLog": "https://downloads.haskell.org/ghc/8.8.3/docs/html/users_guide/8.8.3-notes.html",
        "viTags": [
          "Recommended"
        ]
@@ -2022,6 +2038,7 @@
          "dlSubdir": "cabal-cabal-install-v3.0.0.0/cabal-install",
          "dlUri": "https://github.com/haskell/cabal/archive/cabal-install-v3.0.0.0.tar.gz"
        },
+        "viChangeLog": "https://downloads.haskell.org/~cabal/cabal-install-3.0.0.0/changelog",
        "viTags": []
      },
      "3.2.0.0": {
@@ -2057,6 +2074,7 @@
          "dlSubdir": "cabal-cabal-install-v3.2.0.0/cabal-install",
          "dlUri": "https://github.com/haskell/cabal/archive/cabal-install-v3.2.0.0.tar.gz"
        },
+        "viChangeLog": "https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/changelog",
        "viTags": [
          "Recommended",
          "Latest"
@@ -2109,46 +2127,48 @@
          "dlSubdir": "cabal-cabal-install-v2.4.1.0/cabal-install",
          "dlUri": "https://github.com/haskell/cabal/archive/cabal-install-v2.4.1.0.tar.gz"
        },
+        "viChangeLog": "https://downloads.haskell.org/~cabal/cabal-install-2.4.1.0/changelog",
        "viTags": []
      }
    },
    "GHCup": {
-      "0.1.3": {
+      "0.1.4": {
        "viArch": {
          "A_64": {
            "FreeBSD": {
              "unknown_versioning": {
-                "dlHash": "2daa775d6fa307cb8123fa45ba20e2acd244cdb8cfb3f2b3c8a1aa3f3571c46f",
+                "dlHash": "cda0b959f053abc04ab0a1b9919a505b8c9304e2898a291f527a370cb0e00731",
                "dlSubdir": null,
-                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.3/x86_64-portbld-freebsd-ghcup-0.1.3"
+                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.4/x86_64-portbld-freebsd-ghcup-0.1.4"
              }
            },
            "Darwin": {
              "unknown_versioning": {
-                "dlHash": "a617b06619ec6e75d50dac53f36814c3cafd4dbeebe8cea46d9cd5842c0c94a9",
+                "dlHash": "2422b79933ae037237ccb8f836417b90b3111d7931beb7ae8b9e33a1945c641e",
                "dlSubdir": null,
-                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.3/x86_64-apple-darwin-ghcup-0.1.3"
+                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.4/x86_64-apple-darwin-ghcup-0.1.4"
              }
            },
            "Linux_UnknownLinux": {
              "unknown_versioning": {
-                "dlHash": "873f73b65cf5e399864b81ed597a0e14fa73e0c492429cd3a85fe0fdc585a4c8",
+                "dlHash": "78d69ed4c9a810a445af89ea25e4217a632799ecb427b06cd2320ffb574f555e",
                "dlSubdir": null,
-                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.3/x86_64-linux-ghcup-0.1.3"
+                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.4/x86_64-linux-ghcup-0.1.4"
              }
            }
          },
          "A_32": {
            "Linux_UnknownLinux": {
              "unknown_versioning": {
-                "dlHash": "ff76a6130d6ea869a65bed127255bfa1ddf6aa1bd690df99d872467422c08be0",
+                "dlHash": "057cc1cc39abdacd92cb1d4fb44c850fd9c5398a36b893286248ac5c38bc0c70",
                "dlSubdir": null,
-                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.3/i386-linux-ghcup-0.1.3"
+                "dlUri": "https://downloads.haskell.org/~ghcup/0.1.4/i386-linux-ghcup-0.1.4"
              }
            }
          }
        },
        "viSourceDL": null,
+        "viChangeLog": "https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/CHANGELOG.md",
        "viTags": [
          "Recommended",
          "Latest"
--- a/ghcup-0.0.2.json
+++ b/ghcup-0.0.2.json
--- a/ghcup.cabal
+++ b/ghcup.cabal
@@ -41,9 +41,6 @@ common ascii-string
 common async
  build-depends: async >=0.8

-common attoparsec
-  build-depends: attoparsec >=0.13
-
 common base
  build-depends: base >=4.12 && <5

@@ -230,7 +227,6 @@ library
    , aeson
    , ascii-string
    , async
-    , attoparsec
    , binary
    , bytestring
    , bz2
@@ -248,6 +244,7 @@ library
    , hpath-posix
    , language-bash
    , lzma
+    , megaparsec
    , monad-logger
    , mtl
    , optics
@@ -279,6 +276,9 @@ library

  exposed-modules:
    GHCup
+    GHCup.Data.GHCupDownloads
+    GHCup.Data.GHCupInfo
+    GHCup.Data.ToolRequirements
    GHCup.Download
    GHCup.Download.Utils
    GHCup.Errors
@@ -292,6 +292,7 @@ library
    GHCup.Utils.Dirs
    GHCup.Utils.File
    GHCup.Utils.Logger
+    GHCup.Utils.MegaParsec
    GHCup.Utils.Prelude
    GHCup.Utils.String.QQ
    GHCup.Utils.Version.QQ
@@ -326,8 +327,10 @@ executable ghcup
    , optparse-applicative
    , pretty-terminal
    , resourcet
+    , safe
    , string-interpolate
    , table-layout
+    , template-haskell
    , text
    , uri-bytestring
    , utf8-string
@@ -370,9 +373,6 @@ executable ghcup-gen
  --
  main-is:          Main.hs
  other-modules:
-    GHCupDownloads
-    GHCupInfo
-    ToolRequirements
    Validate

  -- other-extensions:
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
@@ -9,6 +9,7 @@
 {-# LANGUAGE TemplateHaskell       #-}
 {-# LANGUAGE TypeApplications      #-}
 {-# LANGUAGE TypeFamilies          #-}
+{-# LANGUAGE ViewPatterns          #-}

 module GHCup where

@@ -40,6 +41,7 @@ import           Data.ByteString                ( ByteString )
 import           Data.List
 import           Data.Maybe
 import           Data.String.Interpolate
+import           Data.Text                      ( Text )
 import           Data.Versions
 import           Data.Word8
 import           GHC.IO.Exception
@@ -52,11 +54,14 @@ import           Prelude                 hiding ( abs
                                                , writeFile
                                                )
 import           System.IO.Error
+import           System.Posix.Env.ByteString    ( getEnvironment )
 import           System.Posix.FilePath          ( getSearchPath )
 import           System.Posix.Files.ByteString

 import qualified Data.ByteString               as B
+import qualified Data.ByteString.Lazy          as BL
 import qualified Data.Map.Strict               as Map
+import qualified Data.Text                     as T
 import qualified Data.Text.Encoding            as E


@@ -93,45 +98,34 @@ installGHCBin :: ( MonadFail m
                   m
                   ()
 installGHCBin bDls ver mpfReq = do
+  let tver = (mkTVer ver)
  lift $ $(logDebug) [i|Requested to install GHC with #{ver}|]
-  whenM (liftIO $ toolAlreadyInstalled GHC ver)
+  whenM (liftIO $ ghcInstalled tver)
    $ (throwE $ AlreadyInstalled GHC ver)
-  Settings {..} <- lift ask
+  Settings {..}                <- lift ask
  pfreq@(PlatformRequest {..}) <- maybe (liftE $ platformRequest) pure mpfReq

  -- download (or use cached version)
-  dlinfo        <- lE $ getDownloadInfo GHC ver pfreq bDls
-  dl            <- liftE $ downloadCached dlinfo Nothing
+  dlinfo                       <- lE $ getDownloadInfo GHC ver pfreq bDls
+  dl                           <- liftE $ downloadCached dlinfo Nothing

  -- unpack
-  tmpUnpack     <- lift mkGhcupTmpDir
+  tmpUnpack                    <- lift mkGhcupTmpDir
  liftE $ unpackToDir tmpUnpack dl
  void $ liftIO $ darwinNotarization _rPlatform tmpUnpack

  -- prepare paths
-  ghcdir <- liftIO $ ghcupGHCDir ver
+  ghcdir <- liftIO $ ghcupGHCDir tver

  -- the subdir of the archive where we do the work
  let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)

-  -- Be careful about cleanup. We must catch both pure exceptions
-  -- as well as async ones.
-  flip onException
-       (liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-    $ catchAllE
-        (\es -> do
-          liftIO (hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-            >> throwE (BuildFailed workdir es)
-        )
-    $ installGHC' workdir ghcdir
+  liftE $ runBuildAction tmpUnpack (Just ghcdir) (installGHC' workdir ghcdir)

-  -- only clean up dir if the build succeeded
-  liftIO $ deleteDirRecursive tmpUnpack
-
-  liftE $ postGHCInstall ver
+  liftE $ postGHCInstall tver

 where
-    -- | Install an unpacked GHC distribution. This only deals with the GHC build system and nothing else.
+  -- | Install an unpacked GHC distribution. This only deals with the GHC build system and nothing else.
  installGHC' :: (MonadLogger m, MonadIO m)
              => Path Abs      -- ^ Path to the unpacked GHC bindist (where the configure script resides)
              -> Path Abs      -- ^ Path to install to
@@ -172,15 +166,15 @@ installCabalBin :: ( MonadMask m
                     ()
 installCabalBin bDls ver mpfReq = do
  lift $ $(logDebug) [i|Requested to install cabal version #{ver}|]
-  Settings {..} <- lift ask
+  Settings {..}                <- lift ask
  pfreq@(PlatformRequest {..}) <- maybe (liftE $ platformRequest) pure mpfReq

  -- download (or use cached version)
-  dlinfo        <- lE $ getDownloadInfo Cabal ver pfreq bDls
-  dl            <- liftE $ downloadCached dlinfo Nothing
+  dlinfo                       <- lE $ getDownloadInfo Cabal ver pfreq bDls
+  dl                           <- liftE $ downloadCached dlinfo Nothing

  -- unpack
-  tmpUnpack     <- lift withGHCupTmpDir
+  tmpUnpack                    <- lift withGHCupTmpDir
  liftE $ unpackToDir tmpUnpack dl
  void $ liftIO $ darwinNotarization _rPlatform tmpUnpack

@@ -194,7 +188,7 @@ installCabalBin bDls ver mpfReq = do
  pure ()

 where
-    -- | Install an unpacked cabal distribution.
+  -- | Install an unpacked cabal distribution.
  installCabal' :: (MonadLogger m, MonadCatch m, MonadIO m)
                => Path Abs      -- ^ Path to the unpacked cabal bindist (where the executable resides)
                -> Path Abs      -- ^ Path to install to
@@ -226,11 +220,11 @@ installCabalBin bDls ver mpfReq = do
 -- Additionally creates a ~/.ghcup/share -> ~/.ghcup/ghc/<ver>/share symlink
 -- for `SetGHCOnly` constructor.
 setGHC :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
-       => Version
+       => GHCTargetVersion
       -> SetGHC
-       -> Excepts '[NotInstalled] m Version
+       -> Excepts '[NotInstalled] m GHCTargetVersion
 setGHC ver sghc = do
-  let verBS = verToBS ver
+  let verBS = verToBS (_tvVersion ver)
  ghcdir <- liftIO $ ghcupGHCDir ver

  -- symlink destination
@@ -240,7 +234,7 @@ setGHC ver sghc = do
  -- first delete the old symlinks (this fixes compatibility issues
  -- with old ghcup)
  case sghc of
-    SetGHCOnly -> liftE $ rmPlain ver
+    SetGHCOnly -> liftE $ rmPlain (_tvTarget ver)
    SetGHC_XY  -> lift $ rmMajorSymlinks ver
    SetGHC_XYZ -> lift $ rmMinorSymlinks ver

@@ -250,9 +244,8 @@ setGHC ver sghc = do
    targetFile <- case sghc of
      SetGHCOnly -> pure file
      SetGHC_XY  -> do
-        major' <-
-          (\(mj, mi) -> E.encodeUtf8 $ intToText mj <> "." <> intToText mi)
-            <$> getGHCMajor ver
+        major' <- (\(mj, mi) -> E.encodeUtf8 $ intToText mj <> "." <> intToText mi)
+                     <$> getMajorMinorV (_tvVersion ver)
        parseRel (toFilePath file <> B.singleton _hyphen <> major')
      SetGHC_XYZ -> parseRel (toFilePath file <> B.singleton _hyphen <> verBS)

@@ -263,7 +256,7 @@ setGHC ver sghc = do
    liftIO $ createSymlink fullF destL

  -- create symlink for share dir
-  lift $ symlinkShareDir ghcdir verBS
+  when (isNothing . _tvTarget $ ver) $ lift $ symlinkShareDir ghcdir verBS

  pure ver

@@ -303,27 +296,41 @@ data ListCriteria = ListInstalled
 data ListResult = ListResult
  { lTool      :: Tool
  , lVer       :: Version
+  , lCross     :: Maybe Text -- ^ currently only for GHC
  , lTag       :: [Tag]
  , lInstalled :: Bool
-  , lSet       :: Bool
-  , fromSrc    :: Bool
+  , lSet       :: Bool -- ^ currently active version
+  , fromSrc    :: Bool -- ^ compiled from source
+  , lStray     :: Bool -- ^ not in download info
  }
-  deriving Show
+  deriving (Eq, Ord, Show)


-availableToolVersions :: GHCupDownloads -> Tool -> [(Version, [Tag])]
-availableToolVersions av tool = toListOf
-  (ix tool % to (fmap (\(v, vi) -> (v, (_viTags vi))) . Map.toList) % folded)
+availableToolVersions :: GHCupDownloads -> Tool -> Map.Map Version [Tag]
+availableToolVersions av tool = view
+  (at tool % non Map.empty % to (fmap (_viTags)))
  av


-listVersions :: GHCupDownloads
+-- | List all versions from the download info, as well as stray
+-- versions.
+listVersions :: (MonadThrow m, MonadLogger m, MonadIO m)
+             => GHCupDownloads
             -> Maybe Tool
             -> Maybe ListCriteria
-             -> IO [ListResult]
+             -> m [ListResult]
 listVersions av lt criteria = case lt of
  Just t -> do
-    filter' <$> forM (availableToolVersions av t) (toListResult t)
+    -- get versions from GHCupDownloads
+    let avTools = availableToolVersions av t
+    lr <- filter' <$> forM (Map.toList avTools) (liftIO . toListResult t)
+
+    case t of
+      -- append stray GHCs
+      GHC -> do
+        slr <- strayGHCs avTools
+        pure $ (sort (slr ++ lr))
+      _ -> pure lr
  Nothing -> do
    ghcvers   <- listVersions av (Just GHC) criteria
    cabalvers <- listVersions av (Just Cabal) criteria
@@ -331,21 +338,75 @@ listVersions av lt criteria = case lt of
    pure (ghcvers <> cabalvers <> ghcupvers)

 where
+  strayGHCs :: (MonadThrow m, MonadLogger m, MonadIO m)
+            => Map.Map Version [Tag]
+            -> 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 <- liftIO $ ghcSrcInstalled tver
+            pure $ Just $ ListResult
+              { lTool      = GHC
+              , lVer       = _tvVersion
+              , lCross     = Nothing
+              , lTag       = []
+              , lInstalled = True
+              , lStray     = maybe True (const False) (Map.lookup _tvVersion avTools)
+              , ..
+              }
+      Right tver@GHCTargetVersion{ .. } -> do
+        lSet    <- fmap (maybe False (\(GHCTargetVersion _ v ) -> v == _tvVersion)) $ ghcSet _tvTarget
+        fromSrc <- liftIO $ ghcSrcInstalled tver
+        pure $ Just $ ListResult
+          { lTool      = GHC
+          , lVer       = _tvVersion
+          , lCross     = _tvTarget
+          , lTag       = []
+          , lInstalled = True
+          , lStray     = True -- NOTE: cross currently cannot be installed via bindist
+          , ..
+          }
+      Left e -> do
+        $(logWarn)
+          [i|Could not parse version of stray directory #{toFilePath e}|]
+        pure Nothing
+
+  -- NOTE: this are not cross ones, because no bindists
  toListResult :: Tool -> (Version, [Tag]) -> IO ListResult
  toListResult t (v, tags) = case t of
    GHC -> do
-      lSet       <- fmap (maybe False (== v)) $ ghcSet
-      lInstalled <- ghcInstalled v
-      fromSrc    <- ghcSrcInstalled v
-      pure ListResult { lVer = v, lTag = tags, lTool = t, .. }
+      let tver = mkTVer v
+      lSet       <- fmap (maybe False (\(GHCTargetVersion _ v') -> v' == v)) $ ghcSet Nothing
+      lInstalled <- ghcInstalled tver
+      fromSrc    <- ghcSrcInstalled tver
+      pure ListResult { lVer = v, lCross = Nothing , lTag = tags, lTool = t, lStray = False, .. }
    Cabal -> do
      lSet <- fmap (== v) $ cabalSet
      let lInstalled = lSet
-      pure ListResult { lVer = v, lTag = tags, lTool = t, fromSrc = False, .. }
+      pure ListResult { lVer    = v
+                      , lCross  = Nothing
+                      , lTag    = tags
+                      , lTool   = t
+                      , fromSrc = False
+                      , lStray  = False
+                      , ..
+                      }
    GHCup -> do
      let lSet       = prettyPVP ghcUpVer == prettyVer v
      let lInstalled = lSet
-      pure ListResult { lVer = v, lTag = tags, lTool = t, fromSrc = False, .. }
+      pure ListResult { lVer    = v
+                      , lTag    = tags
+                      , lCross  = Nothing
+                      , lTool   = t
+                      , fromSrc = False
+                      , lStray  = False
+                      , ..
+                      }


  filter' :: [ListResult] -> [ListResult]
@@ -363,10 +424,10 @@ listVersions av lt criteria = case lt of

 -- | This function may throw and crash in various ways.
 rmGHCVer :: (MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
-         => Version
+         => GHCTargetVersion
         -> Excepts '[NotInstalled] m ()
 rmGHCVer ver = do
-  isSetGHC <- fmap (maybe False (== ver)) $ ghcSet
+  isSetGHC <- fmap (maybe False (== ver)) $ ghcSet (_tvTarget ver)
  dir      <- liftIO $ ghcupGHCDir ver
  let d' = toFilePath dir
  exists <- liftIO $ doesDirectoryExist dir
@@ -377,7 +438,7 @@ rmGHCVer ver = do
      -- this isn't atomic, order matters
      when isSetGHC $ do
        lift $ $(logInfo) [i|Removing ghc symlinks|]
-        liftE $ rmPlain ver
+        liftE $ rmPlain (_tvTarget ver)

      lift $ $(logInfo) [i|Removing directory recursively: #{d'}|]
      liftIO $ deleteDirRecursive dir
@@ -389,15 +450,15 @@ rmGHCVer ver = do
      -- first remove
      lift $ rmMajorSymlinks ver
      -- then fix them (e.g. with an earlier version)
-      (mj, mi) <- getGHCMajor ver
-      getGHCForMajor mj mi >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+      (mj, mi) <- getMajorMinorV (_tvVersion ver)
+      getGHCForMajor mj mi (_tvTarget ver) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)

      liftIO
        $   ghcupBaseDir
        >>= hideError doesNotExistErrorType
        .   deleteFile
        .   (</> [rel|share|])
-    else throwE (NotInstalled GHC ver)
+    else throwE (NotInstalled GHC (ver ^. tvVersion % to prettyVer))



@@ -438,11 +499,12 @@ compileGHC :: ( MonadMask m
              , MonadFail m
              )
           => GHCupDownloads
-           -> Version                    -- ^ version to install
+           -> GHCTargetVersion           -- ^ version to install
           -> Either Version (Path Abs)  -- ^ version to bootstrap with
           -> Maybe Int                  -- ^ jobs
           -> Maybe (Path Abs)           -- ^ build config
-           -> Maybe (Path Abs)
+           -> Maybe (Path Abs)           -- ^ patch directory
+           -> [Text]                     -- ^ additional args to ./configure
           -> Excepts
                '[ AlreadyInstalled
                 , BuildFailed
@@ -459,13 +521,15 @@ compileGHC :: ( MonadMask m
                 ]
                m
                ()
-compileGHC dls tver bstrap jobs mbuildConfig patchdir = do
+compileGHC dls tver bstrap jobs mbuildConfig patchdir aargs = do
  lift $ $(logDebug) [i|Requested to compile: #{tver} with #{bstrap}|]
-  whenM (liftIO $ toolAlreadyInstalled GHC tver)
-        (throwE $ AlreadyInstalled GHC tver)
+  whenM (liftIO $ ghcInstalled tver)
+        (throwE $ AlreadyInstalled GHC (tver ^. tvVersion))

  -- download source tarball
-  dlInfo    <- preview (ix GHC % ix tver % viSourceDL % _Just) dls ?? NoDownload
+  dlInfo <-
+    preview (ix GHC % ix (tver ^. tvVersion) % viSourceDL % _Just) dls
+      ?? NoDownload
  dl        <- liftE $ downloadCached dlInfo Nothing

  -- unpack
@@ -480,32 +544,29 @@ compileGHC dls tver bstrap jobs mbuildConfig patchdir = do
  let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
  ghcdir <- liftIO $ ghcupGHCDir tver

-  -- Be careful about cleanup. We must catch both pure exceptions
-  -- as well as async ones.
-  flip onException
-       (liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-    $ catchAllE
-        (\es ->
-          liftIO (hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-            >> throwE (BuildFailed workdir es)
-        )
-    $ compile bghc ghcdir workdir
-  markSrcBuilt ghcdir workdir
-
-  -- only clean up dir if the build succeeded
-  liftIO $ deleteDirRecursive tmpUnpack
+  liftE $ runBuildAction
+    tmpUnpack
+    (Just ghcdir)
+    (compile bghc ghcdir workdir >> markSrcBuilt ghcdir workdir)

  reThrowAll GHCupSetError $ postGHCInstall tver
  pure ()

 where
-  defaultConf = [s|
+  defaultConf = case _tvTarget tver of
+                  Nothing -> [s|
 V=0
 BUILD_MAN = NO
 BUILD_SPHINX_HTML = NO
 BUILD_SPHINX_PDF = NO
-HADDOCK_DOCS = YES
-GhcWithLlvmCodeGen = YES|]
+HADDOCK_DOCS = YES|]
+                  Just _ -> [s|
+V=0
+BUILD_MAN = NO
+BUILD_SPHINX_HTML = NO
+BUILD_SPHINX_PDF = NO
+HADDOCK_DOCS = NO
+Stage1Only = YES|]

  compile :: (MonadCatch m, MonadLogger m, MonadIO m)
          => Either (Path Rel) (Path Abs)
@@ -513,6 +574,7 @@ GhcWithLlvmCodeGen = YES|]
          -> Path Abs
          -> Excepts
               '[ FileDoesNotExistError
+                , InvalidBuildConfig
                , PatchFailed
                , ProcessError
                , NotFoundInPATH
@@ -521,14 +583,14 @@ GhcWithLlvmCodeGen = YES|]
               ()
  compile bghc ghcdir workdir = do
    lift $ $(logInfo) [i|configuring build|]
+    liftE $ checkBuildConfig

    forM_ patchdir $ \dir -> liftE $ applyPatches dir workdir

-    -- force ld.bfd for build (others seem to misbehave, like lld from FreeBSD)
-    newEnv <- addToCurrentEnv [("LD", "ld.bfd")]
+    cEnv <- liftIO $ getEnvironment

    if
-      | tver >= [vver|8.8.0|] -> do
+      | (_tvVersion tver) >= [vver|8.8.0|] -> do
        bghcPath <- case bghc of
          Right ghc' -> pure ghc'
          Left  bver -> do
@@ -537,20 +599,32 @@ GhcWithLlvmCodeGen = YES|]
        lEM $ liftIO $ execLogged
          "./configure"
          False
-          ["--prefix=" <> toFilePath ghcdir]
+          (  ["--prefix=" <> toFilePath ghcdir]
+          ++ (maybe mempty
+                    (\x -> ["--target=" <> E.encodeUtf8 x])
+                    (_tvTarget tver)
+             )
+          ++ fmap E.encodeUtf8 aargs
+          )
          [rel|ghc-conf|]
          (Just workdir)
-          (Just (("GHC", toFilePath bghcPath) : newEnv))
+          (Just (("GHC", toFilePath bghcPath) : cEnv))
      | otherwise -> do
        lEM $ liftIO $ execLogged
          "./configure"
          False
-          [ "--prefix=" <> toFilePath ghcdir
-          , "--with-ghc=" <> either toFilePath toFilePath bghc
-          ]
+          (  [ "--prefix=" <> toFilePath ghcdir
+             , "--with-ghc=" <> either toFilePath toFilePath bghc
+             ]
+          ++ (maybe mempty
+                    (\x -> ["--target=" <> E.encodeUtf8 x])
+                    (_tvTarget tver)
+             )
+          ++ fmap E.encodeUtf8 aargs
+          )
          [rel|ghc-conf|]
          (Just workdir)
-          (Just newEnv)
+          (Just cEnv)

    case mbuildConfig of
      Just bc -> liftIOException
@@ -573,6 +647,30 @@ GhcWithLlvmCodeGen = YES|]

  build_mk workdir = workdir </> [rel|mk/build.mk|]

+  checkBuildConfig :: (MonadCatch m, MonadIO m)
+                   => Excepts
+                        '[FileDoesNotExistError , InvalidBuildConfig]
+                        m
+                        ()
+  checkBuildConfig = do
+    c <- case mbuildConfig of
+      Just bc -> do
+        BL.toStrict <$> liftIOException doesNotExistErrorType
+                                        (FileDoesNotExistError $ toFilePath bc)
+                                        (liftIO $ readFile bc)
+      Nothing -> pure defaultConf
+    let lines' = fmap T.strip . T.lines $ decUTF8Safe c
+
+   -- for cross, we need Stage1Only
+    case _tvTarget tver of
+      Just _ -> when (not $ elem "Stage1Only = YES" lines') $ throwE
+        (InvalidBuildConfig
+          [s|Cross compiling needs to be a Stage1 build, add "Stage1Only = YES" to your config!|]
+        )
+      Nothing -> pure ()
+
+
+

 compileCabal :: ( MonadReader Settings m
                , MonadResource m
@@ -613,7 +711,11 @@ compileCabal dls tver bghc jobs patchdir = do

  let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack

-  reThrowAll (BuildFailed workdir) $ compile workdir
+
+  liftE $ runBuildAction
+    tmpUnpack
+    Nothing
+    (compile workdir)

  -- only clean up dir if the build succeeded
  liftIO $ deleteDirRecursive tmpUnpack
@@ -728,12 +830,12 @@ upgradeGHCup dls mtarget force = do
 -- | Creates ghc-x.y.z and ghc-x.y symlinks. This is used for
 -- both installing from source and bindist.
 postGHCInstall :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
-               => Version
+               => GHCTargetVersion
               -> Excepts '[NotInstalled] m ()
-postGHCInstall ver = do
+postGHCInstall ver@GHCTargetVersion{..} = do
  void $ liftE $ setGHC ver SetGHC_XYZ

  -- Create ghc-x.y symlinks. This may not be the current
  -- version, create it regardless.
-  (mj, mi) <- liftIO $ getGHCMajor ver
-  getGHCForMajor mj mi >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+  (mj, mi) <- getMajorMinorV _tvVersion
+  getGHCForMajor mj mi _tvTarget >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
--- a/lib/GHCup/Data/GHCupDownloads.hs
+++ b/lib/GHCup/Data/GHCupDownloads.hs
@@ -2,7 +2,7 @@
 {-# LANGUAGE QuasiQuotes       #-}


-module GHCupDownloads where
+module GHCup.Data.GHCupDownloads where

 import           GHCup.Types
 import           GHCup.Utils.Version.QQ
@@ -827,7 +827,7 @@ ghc_883_32_musl :: DownloadInfo
 ghc_883_32_musl = DownloadInfo
  [uri|https://github.com/redneb/ghc-alt-libc/releases/download/ghc-8.8.3-musl/ghc-8.8.3-i386-unknown-linux-musl.tar.xz|]
  (Just [rel|ghc-8.8.3|])
-  "23779adb4cf4b314d0f8c66ee215ba6e74154c0768a573780475943544020bec"
+  "7a5f41646d06777e75636291a1855d60a0984552bbdf33c3d107565d302f38a4"



@@ -951,6 +951,24 @@ cabal_3000_64_darwin = DownloadInfo
  Nothing
  "d4857e068560515e4cbb0e8ca124c370e07892f2a28804d87152834e5fe2b845"

+cabal_3000_64_freebsd :: DownloadInfo
+cabal_3000_64_freebsd = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-x86_64-portbld-freebsd.tar.xz&dl=1|]
+  Nothing
+  "d97b6469ed612a1367ad1032d0722469ee5277668879694d7d4336233b937516"
+
+cabal_3000_32_alpine :: DownloadInfo
+cabal_3000_32_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-i386-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "a4191cd5a645b00e6a9c53abe6f3cb91fe700de7d7c520c9cb36ce8ec5c9919a"
+
+cabal_3000_64_alpine :: DownloadInfo
+cabal_3000_64_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-x86_64-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "7b35e5986aba4a40fc37141cbde26612bfc916e95a2d2ff35a413612d8c7cd3a"
+


    ---------------------
@@ -976,6 +994,24 @@ cabal_3200_64_darwin = DownloadInfo
  Nothing
  "9197c17d2ece0f934f5b33e323cfcaf486e4681952687bc3d249488ce3cbe0e9"

+cabal_3200_64_freebsd :: DownloadInfo
+cabal_3200_64_freebsd = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-portbld-freebsd.tar.xz&dl=1|]
+  Nothing
+  "e4dc00ab7fef51354e7624dd03e49c6bb684887fc95acb9b33bc52f357a5ef8c"
+
+cabal_3200_32_alpine :: DownloadInfo
+cabal_3200_32_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-i386-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "4aaa52fbc337ae1ef855a2aa2808186580b21ec36883aafec7473e7d899bc5ec"
+
+cabal_3200_64_alpine :: DownloadInfo
+cabal_3200_64_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "c1f3c21a5307cea8d2a0bd9a2eab9f56f3dd90e947ae64e231f909024980992b"
+



@@ -984,32 +1020,32 @@ cabal_3200_64_darwin = DownloadInfo
    -------------


-ghcup_013_32_linux :: DownloadInfo
-ghcup_013_32_linux = DownloadInfo
-  [uri|https://downloads.haskell.org/~ghcup/0.1.3/i386-linux-ghcup-0.1.3|]
+ghcup_014_32_linux :: DownloadInfo
+ghcup_014_32_linux = DownloadInfo
+  [uri|https://downloads.haskell.org/~ghcup/0.1.4/i386-linux-ghcup-0.1.4|]
  Nothing
-  "ff76a6130d6ea869a65bed127255bfa1ddf6aa1bd690df99d872467422c08be0"
+  "057cc1cc39abdacd92cb1d4fb44c850fd9c5398a36b893286248ac5c38bc0c70"


-ghcup_013_64_linux :: DownloadInfo
-ghcup_013_64_linux = DownloadInfo
-  [uri|https://downloads.haskell.org/~ghcup/0.1.3/x86_64-linux-ghcup-0.1.3|]
+ghcup_014_64_linux :: DownloadInfo
+ghcup_014_64_linux = DownloadInfo
+  [uri|https://downloads.haskell.org/~ghcup/0.1.4/x86_64-linux-ghcup-0.1.4|]
  Nothing
-  "873f73b65cf5e399864b81ed597a0e14fa73e0c492429cd3a85fe0fdc585a4c8"
+  "78d69ed4c9a810a445af89ea25e4217a632799ecb427b06cd2320ffb574f555e"


-ghcup_013_64_freebsd :: DownloadInfo
-ghcup_013_64_freebsd = DownloadInfo
-  [uri|https://downloads.haskell.org/~ghcup/0.1.3/x86_64-portbld-freebsd-ghcup-0.1.3|]
+ghcup_014_64_freebsd :: DownloadInfo
+ghcup_014_64_freebsd = DownloadInfo
+  [uri|https://downloads.haskell.org/~ghcup/0.1.4/x86_64-portbld-freebsd-ghcup-0.1.4|]
  Nothing
-  "2daa775d6fa307cb8123fa45ba20e2acd244cdb8cfb3f2b3c8a1aa3f3571c46f"
+  "cda0b959f053abc04ab0a1b9919a505b8c9304e2898a291f527a370cb0e00731"


-ghcup_013_64_darwin10_13 :: DownloadInfo
-ghcup_013_64_darwin10_13 = DownloadInfo
-  [uri|https://downloads.haskell.org/~ghcup/0.1.3/x86_64-apple-darwin-ghcup-0.1.3|]
+ghcup_014_64_darwin10_13 :: DownloadInfo
+ghcup_014_64_darwin10_13 = DownloadInfo
+  [uri|https://downloads.haskell.org/~ghcup/0.1.4/x86_64-apple-darwin-ghcup-0.1.4|]
  Nothing
-  "a617b06619ec6e75d50dac53f36814c3cafd4dbeebe8cea46d9cd5842c0c94a9"
+  "2422b79933ae037237ccb8f836417b90b3111d7931beb7ae8b9e33a1945c641e"



@@ -1026,7 +1062,10 @@ ghcupDownloads = M.fromList
    , M.fromList
      [ ( [vver|7.10.3|]
        , VersionInfo
-            []
+            [Base [pver|4.8.2.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/7.10.3/docs/html/users_guide/release-7-10-1.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/7.10.3/ghc-7.10.3-src.tar.xz|]
              (Just [rel|ghc-7.10.3|])
@@ -1069,7 +1108,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.0.2|]
        , VersionInfo
-            []
+            [Base [pver|4.9.1.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.0.2/docs/html/users_guide/8.0.1-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.0.2/ghc-8.0.2-src.tar.xz|]
              (Just [rel|ghc-8.0.2|])
@@ -1112,7 +1154,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.2.2|]
        , VersionInfo
-            []
+            [Base [pver|4.10.1.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.2.2/docs/html/users_guide/8.2.2-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.2.2/ghc-8.2.2-src.tar.xz|]
              (Just [rel|ghc-8.2.2|])
@@ -1161,7 +1206,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.4.1|]
        , VersionInfo
-            []
+            [Base [pver|4.11.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.4.1/docs/html/users_guide/8.4.1-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.4.1/ghc-8.4.1-src.tar.xz|]
              (Just [rel|ghc-8.4.1|])
@@ -1197,7 +1245,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.4.2|]
        , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.4.2/docs/html/users_guide/8.4.2-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.4.2/ghc-8.4.2-src.tar.xz|]
              (Just [rel|ghc-8.4.2|])
@@ -1244,7 +1295,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.4.3|]
        , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.4.3/docs/html/users_guide/8.4.3-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.4.3/ghc-8.4.3-src.tar.xz|]
              (Just [rel|ghc-8.4.3|])
@@ -1290,7 +1344,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.4.4|]
        , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.4.4/docs/html/users_guide/8.4.4-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.4.4/ghc-8.4.4-src.tar.xz|]
              (Just [rel|ghc-8.4.4|])
@@ -1341,7 +1398,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.6.1|]
        , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.6.1/docs/html/users_guide/8.6.1-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.6.1/ghc-8.6.1-src.tar.xz|]
              (Just [rel|ghc-8.6.1|])
@@ -1388,7 +1448,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.6.2|]
        , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.6.2/docs/html/users_guide/8.6.2-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.6.2/ghc-8.6.2-src.tar.xz|]
              (Just [rel|ghc-8.6.2|])
@@ -1429,7 +1492,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.6.3|]
        , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.6.3/docs/html/users_guide/8.6.3-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.6.3/ghc-8.6.3-src.tar.xz|]
              (Just [rel|ghc-8.6.3|])
@@ -1480,7 +1546,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.6.4|]
        , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.6.4/docs/html/users_guide/8.6.4-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.6.4/ghc-8.6.4-src.tar.xz|]
              (Just [rel|ghc-8.6.4|])
@@ -1526,7 +1595,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.6.5|]
        , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.6.5/docs/html/users_guide/8.6.5-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.6.5/ghc-8.6.5-src.tar.xz|]
              (Just [rel|ghc-8.6.5|])
@@ -1576,7 +1648,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.8.1|]
        , VersionInfo
-            []
+            [Base [pver|4.13.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.8.1/docs/html/users_guide/8.8.1-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.8.1/ghc-8.8.1-src.tar.xz|]
              (Just [rel|ghc-8.8.1|])
@@ -1626,7 +1701,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.8.2|]
        , VersionInfo
-            []
+            [Base [pver|4.13.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.8.2/docs/html/users_guide/8.8.2-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.8.2/ghc-8.8.2-src.tar.xz|]
              (Just [rel|ghc-8.8.2|])
@@ -1676,7 +1754,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.8.3|]
        , VersionInfo
-            [Recommended]
+            [Recommended, Base [pver|4.13.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.8.3/docs/html/users_guide/8.8.3-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.8.3/ghc-8.8.3-src.tar.xz|]
              (Just [rel|ghc-8.8.3|])
@@ -1726,7 +1807,10 @@ ghcupDownloads = M.fromList
        )
      , ( [vver|8.10.1|]
        , VersionInfo
-            [Latest]
+            [Latest, Base [pver|4.14.0.0|]]
+            (Just
+              [uri|https://downloads.haskell.org/ghc/8.10.1/docs/html/users_guide/8.10.1-notes.html|]
+            )
            (Just $ DownloadInfo
              [uri|https://downloads.haskell.org/~ghc/8.10.1/ghc-8.10.1-src.tar.xz|]
              (Just [rel|ghc-8.10.1|])
@@ -1796,6 +1880,9 @@ ghcupDownloads = M.fromList
      [ ( [vver|2.4.1.0|]
        , VersionInfo
            []
+            (Just
+              [uri|https://downloads.haskell.org/~cabal/cabal-install-2.4.1.0/changelog|]
+            )
            (Just $ DownloadInfo
              [uri|https://github.com/haskell/cabal/archive/cabal-install-v2.4.1.0.tar.gz|]
              (Just [rel|cabal-cabal-install-v2.4.1.0/cabal-install|])
@@ -1824,6 +1911,9 @@ ghcupDownloads = M.fromList
      , ( [vver|3.0.0.0|]
        , VersionInfo
            []
+            (Just
+              [uri|https://downloads.haskell.org/~cabal/cabal-install-3.0.0.0/changelog|]
+            )
            (Just $ DownloadInfo
              [uri|https://github.com/haskell/cabal/archive/cabal-install-v3.0.0.0.tar.gz|]
              (Just [rel|cabal-cabal-install-v3.0.0.0/cabal-install|])
@@ -1835,7 +1925,9 @@ ghcupDownloads = M.fromList
                  [ ( Linux UnknownLinux
                    , M.fromList [(Nothing, cabal_3000_64_linux)]
                    )
-                  , (Darwin, M.fromList [(Nothing, cabal_3000_64_darwin)])
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3000_64_alpine)])
+                  , (Darwin      , M.fromList [(Nothing, cabal_3000_64_darwin)])
+                  , (FreeBSD, M.fromList [(Nothing, cabal_3000_64_freebsd)])
                  ]
                )
              , ( A_32
@@ -1843,6 +1935,7 @@ ghcupDownloads = M.fromList
                  [ ( Linux UnknownLinux
                    , M.fromList [(Nothing, cabal_3000_32_linux)]
                    )
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3000_32_alpine)])
                  ]
                )
              ]
@@ -1850,6 +1943,9 @@ ghcupDownloads = M.fromList
      , ( [vver|3.2.0.0|]
        , VersionInfo
            [Recommended, Latest]
+            (Just
+              [uri|https://downloads.haskell.org/~cabal/cabal-install-3.2.0.0/changelog|]
+            )
            (Just $ DownloadInfo
              [uri|https://github.com/haskell/cabal/archive/cabal-install-v3.2.0.0.tar.gz|]
              (Just [rel|cabal-cabal-install-v3.2.0.0/cabal-install|])
@@ -1861,7 +1957,9 @@ ghcupDownloads = M.fromList
                  [ ( Linux UnknownLinux
                    , M.fromList [(Nothing, cabal_3200_64_linux)]
                    )
-                  , (Darwin, M.fromList [(Nothing, cabal_3200_64_darwin)])
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3200_64_alpine)])
+                  , (Darwin      , M.fromList [(Nothing, cabal_3200_64_darwin)])
+                  , (FreeBSD, M.fromList [(Nothing, cabal_3200_64_freebsd)])
                  ]
                )
              , ( A_32
@@ -1869,6 +1967,7 @@ ghcupDownloads = M.fromList
                  [ ( Linux UnknownLinux
                    , M.fromList [(Nothing, cabal_3200_32_linux)]
                    )
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3200_32_alpine)])
                  ]
                )
              ]
@@ -1877,20 +1976,31 @@ ghcupDownloads = M.fromList
    )
  , ( GHCup
    , M.fromList
-      [ ( [vver|0.1.3|]
-        , VersionInfo [Recommended, Latest] Nothing $ M.fromList
-          [ ( A_64
-            , M.fromList
-              [ (Linux UnknownLinux, M.fromList [(Nothing, ghcup_013_64_linux)])
-              , (Darwin, M.fromList [(Nothing, ghcup_013_64_darwin10_13)])
-              , (FreeBSD, M.fromList [(Nothing, ghcup_013_64_freebsd)])
+      [ ( [vver|0.1.4|]
+        , VersionInfo
+            [Recommended, Latest]
+            (Just
+              [uri|https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/CHANGELOG.md|]
+            )
+            Nothing
+          $ M.fromList
+              [ ( A_64
+                , M.fromList
+                  [ ( Linux UnknownLinux
+                    , M.fromList [(Nothing, ghcup_014_64_linux)]
+                    )
+                  , (Darwin , M.fromList [(Nothing, ghcup_014_64_darwin10_13)])
+                  , (FreeBSD, M.fromList [(Nothing, ghcup_014_64_freebsd)])
+                  ]
+                )
+              , ( A_32
+                , M.fromList
+                  [ ( Linux UnknownLinux
+                    , M.fromList [(Nothing, ghcup_014_32_linux)]
+                    )
+                  ]
+                )
              ]
-            )
-          , ( A_32
-            , M.fromList
-              [(Linux UnknownLinux, M.fromList [(Nothing, ghcup_013_32_linux)])]
-            )
-          ]
        )
      ]
    )
--- a/lib/GHCup/Data/GHCupInfo.hs
+++ b/lib/GHCup/Data/GHCupInfo.hs
@@ -1,7 +1,7 @@
-module GHCupInfo where
+module GHCup.Data.GHCupInfo where

-import           GHCupDownloads
-import           ToolRequirements
+import           GHCup.Data.GHCupDownloads
+import           GHCup.Data.ToolRequirements
 import           GHCup.Types


--- a/lib/GHCup/Data/ToolRequirements.hs
+++ b/lib/GHCup/Data/ToolRequirements.hs
@@ -1,7 +1,7 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes       #-}

-module ToolRequirements where
+module GHCup.Data.ToolRequirements where

 import           GHCup.Types
 import           GHCup.Utils.String.QQ
--- a/lib/GHCup/Download.hs
+++ b/lib/GHCup/Download.hs
@@ -192,7 +192,7 @@ getDownloads urlSource = do
      True
      defaultTimeLocale
      "%a, %d %b %Y %H:%M:%S %Z"
-      (T.unpack . E.decodeUtf8 $ h)
+      (T.unpack . decUTF8Safe $ h)

 #endif

@@ -256,7 +256,7 @@ download dli dest mfn
    liftIO $ copyFile fromFile destFile Strict
    pure destFile
  dl = do
-    let uri' = E.decodeUtf8 (serializeURIRef' (view dlUri dli))
+    let uri' = decUTF8Safe (serializeURIRef' (view dlUri dli))
    lift $ $(logInfo) [i|downloading: #{uri'}|]

    -- destination dir must exist
@@ -371,17 +371,17 @@ downloadBS uri'
 #endif


-checkDigest :: (MonadIO m, MonadLogger m, MonadReader Settings m)
+checkDigest :: (MonadIO m, MonadThrow m, MonadLogger m, MonadReader Settings m)
            => DownloadInfo
            -> Path Abs
            -> Excepts '[DigestError] m ()
 checkDigest dli file = do
  verify <- lift ask <&> (not . noVerify)
  when verify $ do
-    let p' = toFilePath file
+    p' <- toFilePath <$> basename file
    lift $ $(logInfo) [i|verifying digest of: #{p'}|]
    c <- liftIO $ readFile file
-    let cDigest = E.decodeUtf8 . B16.encode . SHA256.hashlazy $ c
-        eDigest = view dlHash dli
+    cDigest <- throwEither . E.decodeUtf8' . B16.encode . SHA256.hashlazy $ c
+    let eDigest = view dlHash dli
    when ((cDigest /= eDigest) && verify) $ throwE (DigestError cDigest eDigest)

--- a/lib/GHCup/Download/IOStreams.hs
+++ b/lib/GHCup/Download/IOStreams.hs
@@ -47,7 +47,6 @@ import           URI.ByteString
 import qualified Data.ByteString               as BS
 import qualified Data.ByteString.Lazy          as L
 import qualified Data.Map.Strict               as M
-import qualified Data.Text.Encoding            as E
 import qualified System.IO.Streams             as Streams


@@ -146,7 +145,7 @@ downloadInternal = go (5 :: Int)

    downloadStream r i' = do
      let size = case getHeader r "Content-Length" of
-            Just x' -> case decimal $ E.decodeUtf8 x' of
+            Just x' -> case decimal $ decUTF8Safe x' of
              Left  _       -> 0
              Right (r', _) -> r'
            Nothing -> 0
--- a/lib/GHCup/Errors.hs
+++ b/lib/GHCup/Errors.hs
@@ -64,7 +64,7 @@ data AlreadyInstalled = AlreadyInstalled Tool Version

 -- | The tool is not installed. Some operations rely on a tool
 -- to be installed (such as setting the current GHC version).
-data NotInstalled = NotInstalled Tool Version
+data NotInstalled = NotInstalled Tool Text
  deriving Show

 -- | An executable was expected to be in PATH, but was not found.
@@ -104,6 +104,9 @@ data PatchFailed = PatchFailed
 data NoToolRequirements = NoToolRequirements
  deriving Show

+data InvalidBuildConfig = InvalidBuildConfig Text
+  deriving Show
+

    -------------------------
    --[ High-level errors ]--
--- a/lib/GHCup/Platform.hs
+++ b/lib/GHCup/Platform.hs
@@ -39,7 +39,6 @@ import           System.Info
 import           Text.Regex.Posix

 import qualified Data.Text                     as T
-import qualified Data.Text.Encoding            as E

    --------------------------
    --[ Platform detection ]--
@@ -84,13 +83,13 @@ getPlatform = do
        ( either (const Nothing) Just
          . versioning
          . getMajorVersion
-          . E.decodeUtf8
+          . decUTF8Safe
          )
          <$> getDarwinVersion
      pure $ PlatformResult { _platform = Darwin, _distroVersion = ver }
    "freebsd" -> do
      ver <-
-        (either (const Nothing) Just . versioning . E.decodeUtf8)
+        (either (const Nothing) Just . versioning . decUTF8Safe)
          <$> getFreeBSDVersion
      pure $ PlatformResult { _platform = FreeBSD, _distroVersion = ver }
    what -> throwE $ NoCompatiblePlatform what
@@ -159,7 +158,7 @@ getLinuxDistro = do
    (Just _) <- findExecutable lsb_release_cmd
    name     <- fmap _stdOut $ executeOut lsb_release_cmd ["-si"] Nothing
    ver      <- fmap _stdOut $ executeOut lsb_release_cmd ["-sr"] Nothing
-    pure (E.decodeUtf8 name, Just $ E.decodeUtf8 ver)
+    pure (decUTF8Safe name, Just $ decUTF8Safe ver)

  try_lsb_release :: IO (Text, Maybe Text)
  try_lsb_release = do
@@ -169,7 +168,7 @@ getLinuxDistro = do

  try_redhat_release :: IO (Text, Maybe Text)
  try_redhat_release = do
-    t <- fmap lBS2sT $ readFile redhat_release
+    t <- fmap decUTF8Safe' $ readFile redhat_release
    let nameRegex n =
          makeRegexOpts compIgnoreCase
                        execBlank
@@ -192,4 +191,4 @@ getLinuxDistro = do
  try_debian_version :: IO (Text, Maybe Text)
  try_debian_version = do
    ver <- readFile debian_version
-    pure (T.pack "debian", Just $ lBS2sT ver)
+    pure (T.pack "debian", Just . decUTF8Safe' $ ver)
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -1,4 +1,5 @@
-{-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE OverloadedStrings #-}

 module GHCup.Types where

@@ -70,9 +71,10 @@ data Tool = GHC
 -- | All necessary information of a tool version, including
 -- source download and per-architecture downloads.
 data VersionInfo = VersionInfo
-  { _viTags     :: [Tag]              -- ^ version specific tag
-  , _viSourceDL :: Maybe DownloadInfo -- ^ source tarball
-  , _viArch     :: ArchitectureSpec   -- ^ descend for binary downloads per arch
+  { _viTags      :: [Tag]              -- ^ version specific tag
+  , _viChangeLog :: Maybe URI
+  , _viSourceDL  :: Maybe DownloadInfo -- ^ source tarball
+  , _viArch      :: ArchitectureSpec   -- ^ descend for binary downloads per arch
  }
  deriving (Eq, Show)

@@ -80,7 +82,9 @@ data VersionInfo = VersionInfo
 -- | A tag. These are currently attached to a version of a tool.
 data Tag = Latest
         | Recommended
-         deriving (Ord, Eq, Show)
+         | Base PVP
+         | UnknownTag String  -- ^ used for upwardscompat
+         deriving (Ord, Eq, Show) -- FIXME: manual JSON instance


 data Architecture = A_64
@@ -139,10 +143,17 @@ data URLSource = GHCupURL
 data Settings = Settings
  { cache    :: Bool
  , noVerify :: Bool
+  , keepDirs :: KeepDirs
  }
  deriving Show


+data KeepDirs = Always
+              | Errors
+              | Never
+  deriving (Eq, Show, Ord)
+
+
 data DebugInfo = DebugInfo
  { diBaseDir  :: Path Abs
  , diBinDir   :: Path Abs
@@ -172,3 +183,23 @@ data PlatformRequest = PlatformRequest
  , _rVersion  :: Maybe Versioning
  }
  deriving (Eq, Show)
+
+
+-- | A GHC identified by the target platform triple
+-- and the version.
+data GHCTargetVersion = GHCTargetVersion
+  { _tvTarget  :: Maybe Text
+  , _tvVersion :: Version
+  }
+  deriving (Ord, Eq, Show)
+
+
+mkTVer :: Version -> GHCTargetVersion
+mkTVer = GHCTargetVersion Nothing
+
+
+-- | Assembles a path of the form: <target-triple>-<version>
+prettyTVer :: GHCTargetVersion -> Text
+prettyTVer (GHCTargetVersion (Just t) v') = t <> "-" <> prettyVer v'
+prettyTVer (GHCTargetVersion Nothing  v') = prettyVer v'
+
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -37,14 +37,27 @@ deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Tool
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VSep
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VUnit
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VersionInfo
-deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Tag
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''DownloadInfo
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''GHCupInfo
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Requirements

+instance ToJSON Tag where
+  toJSON Latest             = String "Latest"
+  toJSON Recommended        = String "Recommended"
+  toJSON (Base       pvp'') = String ("base-" <> prettyPVP pvp'')
+  toJSON (UnknownTag x    ) = String (T.pack x)
+
+instance FromJSON Tag where
+  parseJSON = withText "Tag" $ \t -> case T.unpack t of
+    "Latest"                             -> pure Latest
+    "Recommended"                        -> pure Recommended
+    ('b' : 'a' : 's' : 'e' : '-' : ver') -> case pvp (T.pack ver') of
+      Right x -> pure $ Base x
+      Left  e -> fail . show $ e
+    x -> pure (UnknownTag x)

 instance ToJSON URI where
-  toJSON = toJSON . decodeUtf8 . serializeURIRef'
+  toJSON = toJSON . decUTF8Safe . serializeURIRef'

 instance FromJSON URI where
  parseJSON = withText "URL" $ \t ->
@@ -143,6 +156,14 @@ instance FromJSONKey Version where
    Right x -> pure x
    Left  e -> fail $ "Failure in Version (FromJSONKey)" <> show e

+instance ToJSON PVP where
+  toJSON = toJSON . prettyPVP
+
+instance FromJSON PVP where
+  parseJSON = withText "PVP" $ \t -> case pvp t of
+    Right x -> pure x
+    Left  e -> fail $ "Failure in PVP (FromJSON)" <> show e
+
 instance ToJSONKey Tool where
  toJSONKey = genericToJSONKey defaultJSONKeyOptions

@@ -151,7 +172,7 @@ instance FromJSONKey Tool where

 instance ToJSON (Path Rel) where
  toJSON p = case and . fmap isAscii . BS.unpack $ fp of
-    True  -> toJSON . E.decodeUtf8 $ fp
+    True  -> toJSON . decUTF8Safe $ fp
    False -> String "/not/a/valid/path"
    where fp = toFilePath p

--- a/lib/GHCup/Types/Optics.hs
+++ b/lib/GHCup/Types/Optics.hs
@@ -19,6 +19,8 @@ makeLenses ''DownloadInfo
 makeLenses ''Tag
 makeLenses ''VersionInfo

+makeLenses ''GHCTargetVersion
+
 makeLenses ''GHCupInfo

 uriSchemeL' :: Lens' (URIRef Absolute) Scheme
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE QuasiQuotes           #-}
 {-# LANGUAGE TemplateHaskell       #-}
+{-# LANGUAGE ViewPatterns          #-}


 module GHCup.Utils
@@ -15,10 +16,13 @@ where

 import           GHCup.Errors
 import           GHCup.Types
+import           GHCup.Types.Optics
 import           GHCup.Types.JSON               ( )
 import           GHCup.Utils.Dirs
 import           GHCup.Utils.File
+import           GHCup.Utils.MegaParsec
 import           GHCup.Utils.Prelude
+import           GHCup.Utils.String.QQ

 import           Control.Applicative
 import           Control.Exception.Safe
@@ -28,11 +32,12 @@ import           Control.Monad.Fail             ( MonadFail )
 #endif
 import           Control.Monad.Logger
 import           Control.Monad.Reader
-import           Data.Attoparsec.ByteString
 import           Data.ByteString                ( ByteString )
+import           Data.Either
 import           Data.List
 import           Data.Maybe
 import           Data.String.Interpolate
+import           Data.Text                      ( Text )
 import           Data.Versions
 import           Data.Word8
 import           GHC.IO.Exception
@@ -50,6 +55,7 @@ import           System.Posix.FilePath          ( getSearchPath
                                                , takeFileName
                                                )
 import           System.Posix.Files.ByteString  ( readSymbolicLink )
+import           Text.Regex.Posix
 import           URI.ByteString

 import qualified Codec.Archive.Tar             as Tar
@@ -59,7 +65,7 @@ import qualified Codec.Compression.Lzma        as Lzma
 import qualified Data.ByteString               as B
 import qualified Data.Map.Strict               as Map
 import qualified Data.Text.Encoding            as E
-
+import qualified Text.Megaparsec               as MP



@@ -72,62 +78,69 @@ import qualified Data.Text.Encoding            as E

 -- | The symlink destination of a ghc tool.
 ghcLinkDestination :: ByteString -- ^ the tool, such as 'ghc', 'haddock' etc.
-                   -> Version
+                   -> GHCTargetVersion
                   -> ByteString
-ghcLinkDestination tool ver = "../ghc/" <> verToBS ver <> "/bin/" <> tool
-
-
-- | Extract the version part of the result of `ghcLinkDestination`.
-ghcLinkVersion :: MonadThrow m => ByteString -> m Version
-ghcLinkVersion = either (throwM . ParseError) pure . parseOnly parser
- where
-  parser    = string "../ghc/" *> verParser <* string "/bin/ghc"
-  verParser = many1' (notWord8 _slash) >>= \t ->
-    case version $ E.decodeUtf8 $ B.pack t of
-      Left  e -> fail $ show e
-      Right r -> pure r
+ghcLinkDestination tool ver =
+  "../ghc/" <> E.encodeUtf8 (prettyTVer ver) <> "/bin/" <> tool


 -- e.g. ghc-8.6.5
-rmMinorSymlinks :: (MonadIO m, MonadLogger m) => Version -> m ()
-rmMinorSymlinks ver = do
+rmMinorSymlinks :: (MonadIO m, MonadLogger m) => GHCTargetVersion -> m ()
+rmMinorSymlinks GHCTargetVersion {..} = do
  bindir <- liftIO $ ghcupBinDir
-  files  <- liftIO $ getDirsFiles' bindir
-  let myfiles =
-        filter (\x -> ("-" <> verToBS ver) `B.isSuffixOf` toFilePath x) files
-  forM_ myfiles $ \f -> do
+
+  files  <- liftIO $ findFiles'
+    bindir
+    (  maybe mempty (\x -> MP.chunk (x <> "-")) _tvTarget
+    *> parseUntil1 (MP.chunk $ prettyVer _tvVersion)
+    *> (MP.chunk $ prettyVer _tvVersion)
+    *> MP.eof
+    )
+
+  forM_ files $ \f -> do
    let fullF = (bindir </> f)
    $(logDebug) [i|rm -f #{toFilePath fullF}|]
    liftIO $ hideError doesNotExistErrorType $ deleteFile fullF

-- E.g. ghc, if this version is the set one.
-- This reads `ghcupGHCDir`.
+
+-- Removes the set ghc version for the given target, if any.
 rmPlain :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
-        => Version
+  => Maybe Text -- ^ target
        -> Excepts '[NotInstalled] m ()
-rmPlain ver = do
-  files  <- liftE $ ghcToolFiles ver
-  bindir <- liftIO $ ghcupBinDir
-  forM_ files $ \f -> do
-    let fullF = (bindir </> f)
-    lift $ $(logDebug) [i|rm -f #{toFilePath fullF}|]
-    liftIO $ hideError doesNotExistErrorType $ deleteFile fullF
-  -- old ghcup
-  let hdc_file = (bindir </> [rel|haddock-ghc|])
-  lift $ $(logDebug) [i|rm -f #{toFilePath hdc_file}|]
-  liftIO $ hideError doesNotExistErrorType $ deleteFile hdc_file
+rmPlain target = do
+  mtv <- ghcSet target
+  forM_ mtv $ \tv -> do
+    files  <- liftE $ ghcToolFiles tv
+    bindir <- liftIO $ ghcupBinDir
+    forM_ files $ \f -> do
+      let fullF = (bindir </> f)
+      lift $ $(logDebug) [i|rm -f #{toFilePath fullF}|]
+      liftIO $ hideError doesNotExistErrorType $ deleteFile fullF
+    -- old ghcup
+    let hdc_file = (bindir </> [rel|haddock-ghc|])
+    lift $ $(logDebug) [i|rm -f #{toFilePath hdc_file}|]
+    liftIO $ hideError doesNotExistErrorType $ deleteFile hdc_file
+

 -- e.g. ghc-8.6
-rmMajorSymlinks :: (MonadLogger m, MonadIO m) => Version -> m ()
-rmMajorSymlinks ver = do
-  (mj, mi) <- liftIO $ getGHCMajor ver
-  let v' = E.encodeUtf8 $ intToText mj <> "." <> intToText mi
+rmMajorSymlinks :: (MonadThrow m, MonadLogger m, MonadIO m)
+                => GHCTargetVersion
+                -> m ()
+rmMajorSymlinks GHCTargetVersion {..} = do
+  (mj, mi) <- getMajorMinorV _tvVersion
+  let v' = intToText mj <> "." <> intToText mi

  bindir <- liftIO ghcupBinDir

-  files  <- liftIO $ getDirsFiles' bindir
-  let myfiles = filter (\x -> ("-" <> v') `B.isSuffixOf` toFilePath x) files
-  forM_ myfiles $ \f -> do
+  files  <- liftIO $ findFiles'
+    bindir
+    (  maybe mempty (\x -> MP.chunk (x <> "-")) _tvTarget
+    *> parseUntil1 (MP.chunk v')
+    *> MP.chunk v'
+    *> MP.eof
+    )
+
+  forM_ files $ \f -> do
    let fullF = (bindir </> f)
    $(logDebug) [i|rm -f #{toFilePath fullF}|]
    liftIO $ hideError doesNotExistErrorType $ deleteFile fullF
@@ -140,33 +153,60 @@ rmMajorSymlinks ver = do
    -----------------------------------


-toolAlreadyInstalled :: Tool -> Version -> IO Bool
-toolAlreadyInstalled tool ver = case tool of
-  GHC   -> ghcInstalled ver
-  Cabal -> cabalInstalled ver
-  GHCup -> pure True
-
-
-ghcInstalled :: Version -> IO Bool
+ghcInstalled :: GHCTargetVersion -> IO Bool
 ghcInstalled ver = do
  ghcdir <- ghcupGHCDir ver
  doesDirectoryExist ghcdir


-ghcSrcInstalled :: Version -> IO Bool
+ghcSrcInstalled :: GHCTargetVersion -> IO Bool
 ghcSrcInstalled ver = do
  ghcdir <- ghcupGHCDir ver
  doesFileExist (ghcdir </> ghcUpSrcBuiltFile)


-ghcSet :: (MonadIO m, MonadThrow m) => m (Maybe Version)
-ghcSet = do
-  ghcBin <- (</> [rel|ghc|]) <$> liftIO ghcupBinDir
+ghcSet :: (MonadThrow m, MonadIO m)
+       => Maybe Text   -- ^ the target of the GHC version, if any
+                       --  (e.g. armv7-unknown-linux-gnueabihf)
+       -> m (Maybe GHCTargetVersion)
+ghcSet mtarget = do
+  ghc    <- parseRel $ E.encodeUtf8 (maybe "ghc" (<> "-ghc") mtarget)
+  ghcBin <- (</> ghc) <$> liftIO ghcupBinDir

  -- link destination is of the form ../ghc/<ver>/bin/ghc
  liftIO $ handleIO' NoSuchThing (\_ -> pure $ Nothing) $ do
    link <- readSymbolicLink $ toFilePath ghcBin
    Just <$> ghcLinkVersion link
+ where
+  ghcLinkVersion :: MonadThrow m => ByteString -> m GHCTargetVersion
+  ghcLinkVersion bs = do
+    t <- throwEither $ E.decodeUtf8' bs
+    throwEither $ MP.parse parser "" t
+   where
+    parser =
+      MP.chunk "../ghc/"
+        *> (do
+             r    <- parseUntil1 (MP.chunk "/")
+             rest <- MP.getInput
+             MP.setInput r
+             x <- ghcTargetVerP
+             MP.setInput rest
+             pure x
+           )
+        <* MP.chunk "/bin/"
+        <* ghcTargetBinP "ghc"
+        <* MP.eof
+
+
+-- | Get all installed GHCs by reading ~/.ghcup/ghc/<dir>.
+-- If a dir cannot be parsed, returns left.
+getInstalledGHCs :: MonadIO m => m [Either (Path Rel) GHCTargetVersion]
+getInstalledGHCs = do
+  ghcdir <- liftIO $ ghcupGHCBaseDir
+  fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ getDirsFiles' ghcdir
+  forM fs $ \f -> case parseGHCupGHCDir f of
+    Right r -> pure $ Right r
+    Left  _ -> pure $ Left f


 cabalInstalled :: Version -> IO Bool
@@ -179,7 +219,7 @@ cabalSet = do
  cabalbin <- (</> [rel|cabal|]) <$> liftIO ghcupBinDir
  mc       <- liftIO $ executeOut cabalbin ["--numeric-version"] Nothing
  let reportedVer = fst . B.spanEnd (== _lf) . _stdOut $ mc
-  case version (E.decodeUtf8 reportedVer) of
+  case version $ decUTF8Safe reportedVer of
    Left  e -> throwM e
    Right r -> pure r

@@ -190,32 +230,49 @@ cabalSet = do
    -----------------------------------------


-- | We assume GHC is in semver format. I hope it is.
-getGHCMajor :: MonadThrow m => Version -> m (Int, Int)
-getGHCMajor ver = do
-  SemVer {..} <- throwEither (semver $ prettyVer ver)
-  pure (fromIntegral _svMajor, fromIntegral _svMinor)
+getMajorMinorV :: MonadThrow m => Version -> m (Int, Int)
+getMajorMinorV Version {..} = case _vChunks of
+  ([Digits x] : [Digits y] : _) -> pure (fromIntegral x, fromIntegral y)
+  _ -> throwM $ ParseError "Could not parse X.Y from version"
+
+
+matchMajor :: Version -> Int -> Int -> Bool
+matchMajor v' major' minor' = case getMajorMinorV v' of
+  Just (x, y) -> x == major' && y == minor'
+  Nothing     -> False


 -- | Get the latest installed full GHC version that satisfies X.Y.
 -- This reads `ghcupGHCBaseDir`.
 getGHCForMajor :: (MonadIO m, MonadThrow m)
-               => Int -- ^ major version component
-               -> Int -- ^ minor version component
-               -> m (Maybe Version)
-getGHCForMajor major' minor' = do
-  p       <- liftIO $ ghcupGHCBaseDir
-  ghcs    <- liftIO $ getDirsFiles' p
-  semvers <- forM ghcs $ throwEither . semver . E.decodeUtf8 . toFilePath
-  mapM (throwEither . version)
-    . fmap prettySemVer
+               => Int        -- ^ major version component
+               -> Int        -- ^ minor version component
+               -> Maybe Text -- ^ the target triple
+               -> m (Maybe GHCTargetVersion)
+getGHCForMajor major' minor' mt = do
+  ghcs <- rights <$> getInstalledGHCs
+
+  pure
    . lastMay
-    . sort
+    . sortBy (\x y -> compare (_tvVersion x) (_tvVersion y))
    . filter
-        (\SemVer {..} ->
-          fromIntegral _svMajor == major' && fromIntegral _svMinor == minor'
+        (\GHCTargetVersion {..} ->
+          _tvTarget == mt && matchMajor _tvVersion major' minor'
        )
-    $ semvers
+    $ ghcs
+
+
+-- | Get the latest available ghc for X.Y major version.
+getLatestGHCFor :: Int -- ^ major version component
+                -> Int -- ^ minor version component
+                -> GHCupDownloads
+                -> Maybe Version
+getLatestGHCFor major' minor' dls = do
+  join
+    . fmap (lastMay . filter (\v -> matchMajor v major' minor'))
+    . preview (ix GHC % to Map.keys)
+    $ dls
+



@@ -232,8 +289,9 @@ unpackToDir :: (MonadLogger m, MonadIO m, MonadThrow m)
            -> Path Abs       -- ^ archive path
            -> Excepts '[UnknownArchive] m ()
 unpackToDir dest av = do
-  let fp = E.decodeUtf8 (toFilePath av)
-  lift $ $(logInfo) [i|Unpacking: #{fp}|]
+  fp <- (decUTF8Safe . toFilePath) <$> basename av
+  let dfp = decUTF8Safe . toFilePath $ dest
+  lift $ $(logInfo) [i|Unpacking: #{fp} to #{dfp}|]
  fn <- toFilePath <$> basename av
  let untar = Tar.unpack (toFilePath dest) . Tar.read

@@ -258,21 +316,27 @@ unpackToDir dest av = do
    ------------


-- | Get the tool versions that have this tag.
-getTagged :: GHCupDownloads -> Tool -> Tag -> [Version]
-getTagged av tool tag = toListOf
-  ( ix tool
-  % to (Map.filter (\VersionInfo {..} -> elem tag _viTags))
-  % to Map.keys
-  % folded
+-- | Get the tool version that has this tag. If multiple have it,
+-- picks the greatest version.
+getTagged :: Tag
+          -> AffineFold (Map.Map Version VersionInfo) (Version, VersionInfo)
+getTagged tag =
+  ( to (Map.filter (\VersionInfo {..} -> elem tag _viTags))
+  % to Map.toDescList
+  % _head
  )
-  av

 getLatest :: GHCupDownloads -> Tool -> Maybe Version
-getLatest av tool = headOf folded $ getTagged av tool Latest
+getLatest av tool = headOf (ix tool % getTagged Latest % to fst) $ av

 getRecommended :: GHCupDownloads -> Tool -> Maybe Version
-getRecommended av tool = headOf folded $ getTagged av tool Recommended
+getRecommended av tool = headOf (ix tool % getTagged Recommended % to fst) $ av
+
+
+-- | Gets the latest GHC with a given base version.
+getLatestBaseVersion :: GHCupDownloads -> PVP -> Maybe Version
+getLatestBaseVersion av pvpVer =
+  headOf (ix GHC % getTagged (Base pvpVer) % to fst) av



@@ -298,12 +362,12 @@ urlBaseName = parseRel . snd . B.breakEnd (== _slash) . urlDecode False


 -- Get tool files from '~/.ghcup/bin/ghc/<ver>/bin/*'
-- while ignoring *-<ver> symlinks.
+-- while ignoring *-<ver> symlinks and accounting for cross triple prefix.
 --
 -- Returns unversioned relative files, e.g.:
 --   ["hsc2hs","haddock","hpc","runhaskell","ghc","ghc-pkg","ghci","runghc","hp2ps"]
 ghcToolFiles :: (MonadThrow m, MonadFail m, MonadIO m)
-             => Version
+             => GHCTargetVersion
             -> Excepts '[NotInstalled] m [Path Rel]
 ghcToolFiles ver = do
  ghcdir <- liftIO $ ghcupGHCDir ver
@@ -311,18 +375,28 @@ ghcToolFiles ver = do

  -- fail if ghc is not installed
  whenM (fmap not $ liftIO $ doesDirectoryExist ghcdir)
-        (throwE (NotInstalled GHC ver))
+        (throwE (NotInstalled GHC (prettyTVer ver)))

-  files         <- liftIO $ getDirsFiles' bindir
+  files    <- liftIO $ getDirsFiles' bindir
  -- figure out the <ver> suffix, because this might not be `Version` for
  -- alpha/rc releases, but x.y.a.somedate.
+
+  -- for cross, this won't be "ghc", but e.g.
+  -- "armv7-unknown-linux-gnueabihf-ghc"
+  [ghcbin] <- liftIO $ findFiles
+    bindir
+    (makeRegexOpts compExtended
+                   execBlank
+                   ([s|^([a-zA-Z0-9_-]*[a-zA-Z0-9_]-)?ghc$|] :: ByteString)
+    )
+
  (Just symver) <-
-    (B.stripPrefix "ghc-" . takeFileName)
-      <$> (liftIO $ readSymbolicLink $ toFilePath (bindir </> [rel|ghc|]))
+    (B.stripPrefix (toFilePath ghcbin <> "-") . takeFileName)
+      <$> (liftIO $ readSymbolicLink $ toFilePath (bindir </> ghcbin))
  when (B.null symver)
       (throwIO $ userError $ "Fatal: ghc symlink target is broken")

-  pure $ filter (\x -> not $ symver `B.isSuffixOf` toFilePath x) files
+  pure . filter (\x -> not $ symver `B.isSuffixOf` toFilePath x) $ files


 -- | This file, when residing in ~/.ghcup/ghc/<ver>/ signals that
@@ -368,3 +442,47 @@ darwinNotarization Darwin path = exec
  Nothing
  Nothing
 darwinNotarization _ _ = pure $ Right ()
+
+
+getChangeLog :: GHCupDownloads -> Tool -> Either Version Tag -> Maybe URI
+getChangeLog dls tool (Left v') =
+  preview (ix tool % ix v' % viChangeLog % _Just) dls
+getChangeLog dls tool (Right tag) =
+  preview (ix tool % getTagged tag % to snd % viChangeLog % _Just) dls
+
+
+-- | 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 :: (Show (V e), MonadReader Settings m, MonadIO m, MonadMask m)
+               => Path Abs          -- ^ build directory
+               -> Maybe (Path Abs)  -- ^ install location (e.g. for GHC)
+               -> Excepts e m ()
+               -> Excepts '[BuildFailed] m ()
+runBuildAction bdir instdir action = do
+  Settings {..} <- lift ask
+  flip
+      onException
+      (do
+        forM_ instdir $ \dir ->
+          liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
+        when (keepDirs == Never)
+          $ liftIO
+          $ hideError doesNotExistErrorType
+          $ deleteDirRecursive bdir
+      )
+    $ catchAllE
+        (\es -> do
+          forM_ instdir $ \dir ->
+            liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
+          when (keepDirs == Never)
+            $ liftIO
+            $ hideError doesNotExistErrorType
+            $ deleteDirRecursive bdir
+          throwE (BuildFailed bdir es)
+        )
+    $ action
+
+  when (keepDirs == Never || keepDirs == Errors) $ liftIO $ deleteDirRecursive
+    bdir
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -1,10 +1,13 @@
 {-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE QuasiQuotes           #-}
+{-# LANGUAGE ViewPatterns          #-}

 module GHCup.Utils.Dirs where


+import           GHCup.Types
 import           GHCup.Types.JSON               ( )
+import           GHCup.Utils.MegaParsec
 import           GHCup.Utils.Prelude

 import           Control.Applicative
@@ -13,7 +16,6 @@ import           Control.Monad
 import           Control.Monad.Reader
 import           Control.Monad.Trans.Resource
 import           Data.Maybe
-import           Data.Versions
 import           HPath
 import           HPath.IO
 import           Optics
@@ -27,8 +29,10 @@ import           System.Posix.Env.ByteString    ( getEnv
 import           System.Posix.Temp.ByteString   ( mkdtemp )

 import qualified Data.ByteString.UTF8          as UTF8
+import qualified Data.Text.Encoding            as E
 import qualified System.Posix.FilePath         as FP
 import qualified System.Posix.User             as PU
+import qualified Text.Megaparsec               as MP



@@ -37,6 +41,7 @@ import qualified System.Posix.User             as PU
    -------------------------


+-- | ~/.ghcup by default
 ghcupBaseDir :: IO (Path Abs)
 ghcupBaseDir = do
  bdir <- getEnv "GHCUP_INSTALL_BASE_PREFIX" >>= \case
@@ -44,16 +49,30 @@ ghcupBaseDir = do
    Nothing -> liftIO getHomeDirectory
  pure (bdir </> [rel|.ghcup|])

+
+-- | ~/.ghcup/ghc by default.
 ghcupGHCBaseDir :: IO (Path Abs)
 ghcupGHCBaseDir = ghcupBaseDir <&> (</> [rel|ghc|])

-ghcupGHCDir :: Version -> IO (Path Abs)
+
+-- | Gets '~/.ghcup/ghc/<ghcupGHCDir>'.
+-- The dir may be of the form
+--   * armv7-unknown-linux-gnueabihf-8.8.3
+--   * 8.8.4
+ghcupGHCDir :: GHCTargetVersion -> IO (Path Abs)
 ghcupGHCDir ver = do
  ghcbasedir <- ghcupGHCBaseDir
-  verdir     <- parseRel (verToBS ver)
+  verdir     <- parseRel $ E.encodeUtf8 (prettyTVer ver)
  pure (ghcbasedir </> verdir)


+-- | See 'ghcupToolParser'.
+parseGHCupGHCDir :: MonadThrow m => Path Rel -> m GHCTargetVersion
+parseGHCupGHCDir (toFilePath -> f) = do
+  fp <- throwEither $ E.decodeUtf8' f
+  throwEither $ MP.parse ghcTargetVerP "" fp
+
+
 ghcupBinDir :: IO (Path Abs)
 ghcupBinDir = ghcupBaseDir <&> (</> [rel|bin|])

--- a/lib/GHCup/Utils/File.hs
+++ b/lib/GHCup/Utils/File.hs
@@ -18,6 +18,8 @@ import           Data.Foldable
 import           Data.Functor
 import           Data.IORef
 import           Data.Maybe
+import           Data.Text                      ( Text )
+import           Data.Void
 import           GHC.Foreign                    ( peekCStringLen )
 import           GHC.IO.Encoding                ( getLocaleEncoding )
 import           GHC.IO.Exception
@@ -39,12 +41,12 @@ import "unix"    System.Posix.IO.ByteString
                                         hiding ( openFd )
 import           System.Posix.Process           ( ProcessStatus(..) )
 import           System.Posix.Types
+import           Text.Regex.Posix


 import qualified Control.Exception             as EX
 import qualified Data.Text                     as T
 import qualified Data.Text.Encoding            as E
-import qualified Data.Text.Encoding.Error      as E
 import qualified System.Posix.Process.ByteString
                                               as SPPB
 import           Streamly.External.Posix.DirStream
@@ -53,12 +55,14 @@ import qualified Streamly.Internal.Memory.ArrayStream
 import qualified Streamly.FileSystem.Handle    as FH
 import qualified Streamly.Internal.Data.Unfold as SU
 import qualified Streamly.Prelude              as S
+import qualified Text.Megaparsec               as MP
 import qualified Data.ByteString               as BS
 import qualified Data.ByteString.Lazy          as L
 import qualified "unix-bytestring" System.Posix.IO.ByteString
                                               as SPIB


+
 -- | Bool signals whether the regions should be cleaned.
 data StopThread = StopThread Bool
  deriving Show
@@ -201,6 +205,7 @@ execLogged exe spath args lfile chdir env = do
    lineAction ref rs bs' = do
      modifyIORef' ref (swapRegs bs')
      regs <- readIORef ref
+      void $ SPIB.fdWrite fileFd (bs' <> "\n")
      forM (zip regs rs) $ \(bs, r) -> do
        setConsoleRegion r $ do
          w <- consoleWidth
@@ -208,12 +213,10 @@ execLogged exe spath args lfile chdir env = do
            . T.pack
            . color Blue
            . T.unpack
-            . E.decodeUtf8With E.lenientDecode
+            . decUTF8Safe
            . trim w
            . (\b -> "[ " <> toFilePath lfile <> " ] " <> b)
            $ bs
-        SPIB.fdWrite fileFd (bs <> "\n")
-

    swapRegs bs regs | length regs < size = regs ++ [bs]
                     | otherwise          = tail regs ++ [bs]
@@ -371,8 +374,7 @@ searchPath paths needle = go paths
 where
  go [] = pure Nothing
  go (x : xs) =
-    hideErrorDefM PermissionDenied (go xs)
-      $ hideErrorDefM NoSuchThing (go xs)
+    hideErrorDefM [InappropriateType, PermissionDenied, NoSuchThing] (go xs)
      $ do
          dirStream <- openDirStream (toFilePath x)
          S.findM (\(_, p) -> isMatch x p) (dirContentsStream dirStream)
@@ -383,3 +385,27 @@ searchPath paths needle = go paths
    if p == toFilePath needle
      then isExecutable (basedir </> needle)
      else pure False
+
+
+findFiles :: Path Abs -> Regex -> IO [Path Rel]
+findFiles path regex = do
+  dirStream <- openDirStream (toFilePath path)
+  f         <-
+    (fmap . fmap) snd
+    . S.toList
+    . S.filter (\(_, p) -> match regex p)
+    $ dirContentsStream dirStream
+  pure $ join $ fmap parseRel f
+
+
+findFiles' :: Path Abs -> MP.Parsec Void Text () -> IO [Path Rel]
+findFiles' path parser = do
+  dirStream <- openDirStream (toFilePath path)
+  f         <-
+    (fmap . fmap) snd
+    . S.toList
+    . S.filter (\(_, p) -> case E.decodeUtf8' p of
+                             Left _ -> False
+                             Right p' -> isJust $ MP.parseMaybe parser p')
+    $ dirContentsStream dirStream
+  pure $ join $ fmap parseRel f
--- a/lib/GHCup/Utils/MegaParsec.hs
+++ b/lib/GHCup/Utils/MegaParsec.hs
@@ -0,0 +1,87 @@
+{-# LANGUAGE CPP                  #-}
+{-# LANGUAGE OverloadedStrings    #-}
+
+module GHCup.Utils.MegaParsec where
+
+import           GHCup.Types
+
+import           Control.Applicative
+import           Control.Monad
+#if !MIN_VERSION_base(4,13,0)
+import           Control.Monad.Fail             ( MonadFail )
+#endif
+import           Data.Functor
+import           Data.Maybe
+import           Data.Text                      ( Text )
+import           Data.Versions
+import           Data.Void
+
+import qualified Data.Text                     as T
+import qualified Text.Megaparsec               as MP
+
+
+choice' :: (MonadFail f, MP.MonadParsec e s f) => [f a] -> f a
+choice' []       = fail "Empty list"
+choice' [x     ] = x
+choice' (x : xs) = MP.try x <|> choice' xs
+
+
+parseUntil :: MP.Parsec Void Text a -> MP.Parsec Void Text Text
+parseUntil p = do
+  (MP.try (MP.lookAhead p) $> mempty)
+    <|> (do
+          c  <- T.singleton <$> MP.anySingle
+          c2 <- parseUntil p
+          pure (c `mappend` c2)
+        )
+
+parseUntil1 :: MP.Parsec Void Text a -> MP.Parsec Void Text Text
+parseUntil1 p = do
+  i1 <- MP.getOffset
+  t <- parseUntil p
+  i2 <- MP.getOffset
+  if i1 == i2 then fail "empty parse" else pure t
+
+
+
+-- | Parses e.g.
+--   * armv7-unknown-linux-gnueabihf-ghc
+--   * armv7-unknown-linux-gnueabihf-ghci
+ghcTargetBinP :: Text -> MP.Parsec Void Text (Maybe Text, Text)
+ghcTargetBinP t =
+  (,)
+    <$> (   MP.try
+            (Just <$> (parseUntil1 (MP.chunk "-" *> MP.chunk t)) <* MP.chunk "-"
+            )
+        <|> (flip const Nothing <$> mempty)
+        )
+    <*> (MP.chunk t <* MP.eof)
+
+
+-- | Extracts target triple and version from e.g.
+--   * armv7-unknown-linux-gnueabihf-8.8.3
+--   * armv7-unknown-linux-gnueabihf-8.8.3
+ghcTargetVerP :: MP.Parsec Void Text GHCTargetVersion
+ghcTargetVerP =
+  (\x y -> GHCTargetVersion x y)
+    <$> (MP.try (Just <$> (parseUntil1 (MP.chunk "-" *> verP)) <* MP.chunk "-")
+        <|> (flip const Nothing <$> mempty)
+        )
+    <*> (version' <* MP.eof)
+ where
+  verP :: MP.Parsec Void Text Text
+  verP = do
+    v <- version'
+    let startsWithDigists =
+          and
+            . take 3
+            . join
+            . (fmap . fmap)
+                (\case
+                  (Digits _) -> True
+                  (Str    _) -> False
+                )
+            $ (_vChunks v)
+    if startsWithDigists && not (isJust (_vEpoch v))
+      then pure $ prettyVer v
+      else fail "Oh"
--- a/lib/GHCup/Utils/Prelude.hs
+++ b/lib/GHCup/Utils/Prelude.hs
@@ -29,6 +29,7 @@ import qualified Data.ByteString.Lazy          as L
 import qualified Data.Strict.Maybe             as S
 import qualified Data.Text                     as T
 import qualified Data.Text.Encoding            as E
+import qualified Data.Text.Encoding.Error      as E
 import qualified Data.Text.Lazy                as TL
 import qualified Data.Text.Lazy.Builder        as B
 import qualified Data.Text.Lazy.Builder.Int    as B
@@ -87,10 +88,6 @@ whileM_ ~action = void . whileM action
 guardM :: (Monad m, Alternative m) => m Bool -> m ()
 guardM ~f = guard =<< f

-lBS2sT :: L.ByteString -> Text
-lBS2sT = TL.toStrict . TLE.decodeUtf8
-
-

 handleIO' :: (MonadIO m, MonadCatch m)
          => IOErrorType
@@ -168,14 +165,14 @@ liftIOException errType ex =
    . lift


-hideErrorDef :: IOErrorType -> a -> IO a -> IO a
-hideErrorDef err def =
-  handleIO (\e -> if err == ioeGetErrorType e then pure def else ioError e)
+hideErrorDef :: [IOErrorType] -> a -> IO a -> IO a
+hideErrorDef errs def =
+  handleIO (\e -> if ioeGetErrorType e `elem` errs then pure def else ioError e)


-hideErrorDefM :: IOErrorType -> IO a -> IO a -> IO a
-hideErrorDefM err def =
-  handleIO (\e -> if err == ioeGetErrorType e then def else ioError e)
+hideErrorDefM :: [IOErrorType] -> IO a -> IO a -> IO a
+hideErrorDefM errs def =
+  handleIO (\e -> if ioeGetErrorType e `elem` errs then def else ioError e)


 -- TODO: does this work?
@@ -221,6 +218,12 @@ throwEither a = case a of
  Right r -> pure r


+throwEither' :: (Exception a, MonadThrow m) => a -> Either x b -> m b
+throwEither' e eth = case eth of
+  Left  _ -> throwM e
+  Right r -> pure r
+
+
 verToBS :: Version -> ByteString
 verToBS = E.encodeUtf8 . prettyVer

@@ -243,4 +246,16 @@ addToCurrentEnv adds = do


 pvpToVersion :: PVP -> Version
-pvpToVersion = either (\_ -> error "Couldn't convert PVP to Version") id . version . prettyPVP
+pvpToVersion =
+  either (\_ -> error "Couldn't convert PVP to Version") id
+    . version
+    . prettyPVP
+
+
+-- | Safe 'decodeUtf8With'. Replaces an invalid input byte with
+-- the Unicode replacement character U+FFFD.
+decUTF8Safe :: ByteString -> Text
+decUTF8Safe = E.decodeUtf8With E.lenientDecode
+
+decUTF8Safe' :: L.ByteString -> Text
+decUTF8Safe' = TL.toStrict . TLE.decodeUtf8With E.lenientDecode
--- a/lib/GHCup/Version.hs
+++ b/lib/GHCup/Version.hs
@@ -9,9 +9,14 @@ import           Data.Versions
 import           URI.ByteString
 import           URI.ByteString.QQ

+import qualified Data.Text                     as T
+
 -- | This reflects the API version of the JSON.
 ghcupURL :: URI
-ghcupURL = [uri|https://www.haskell.org/ghcup/data/ghcup-0.0.1.json|]
+ghcupURL = [uri|https://www.haskell.org/ghcup/data/ghcup-0.0.2.json|]

 ghcUpVer :: PVP
 ghcUpVer = [pver|0.1.4|]
+
+numericVer :: String
+numericVer = T.unpack . prettyPVP $ ghcUpVer
Author	SHA1	Message	Date
Julian Ospald	bc0cd22433	First cross try	2020-04-27 07:49:08 +02:00
Julian Ospald	ed4ff15f96	Update bash-completion	2020-04-27 07:47:46 +02:00
Julian Ospald	1d623723a2	Fix bug with missing ~/.ghcup/ghc/ dir	2020-04-26 22:06:00 +02:00
Julian Ospald	931080244f	Fix bug in logging	2020-04-26 20:17:59 +02:00
Julian Ospald	27e2e7f848	Fix building of documentation	2020-04-26 11:55:47 +02:00
Julian Ospald	8b638c7ecb	Rm stray ghc version	2020-04-25 13:22:12 +02:00
Julian Ospald	acd370611f	Fix gitlab CI	2020-04-25 13:02:34 +02:00
Julian Ospald	e1b5a89cee	Add bash-completion	2020-04-22 21:45:33 +02:00
Julian Ospald	5edebd57d9	Move download info into library	2020-04-22 19:32:48 +02:00
Julian Ospald	bcaccaaf31	Implement --keep	2020-04-22 19:32:14 +02:00
Julian Ospald	818a5d2d85	Document environment variables	2020-04-22 16:14:10 +02:00
Julian Ospald	13acce07d4	Allow to install X.Y versions	2020-04-22 16:13:58 +02:00
Julian Ospald	4ed5e21b7f	Validate that all GHC versions have a base tag	2020-04-22 16:13:23 +02:00
Julian Ospald	86aab6bb59	Improve output formatting	2020-04-22 16:12:56 +02:00
Julian Ospald	7f5cb64b18	Re-add --format-raw to list subcommand	2020-04-22 13:03:46 +02:00
Julian Ospald	6c12eb16eb	Add base tag	2020-04-22 11:59:40 +02:00
Julian Ospald	e637f90fae	List stray tools	2020-04-21 23:37:48 +02:00
Julian Ospald	5b33c3f491	Update TODO	2020-04-19 22:49:19 +02:00
Julian Ospald	1842ed464f	Also build 32bit release artifact	2020-04-19 22:31:53 +02:00
Julian Ospald	296bbdd561	Fix digest of ghc-8.8.3-i386-unknown-linux-musl.tar.xz	2020-04-19 22:05:18 +02:00
Julian Ospald	27ead1be7c	Build releases	2020-04-19 18:55:07 +02:00
Julian Ospald	5184609dba	Enable FreeBSD testing Also use the new ghcup for bootstrapping GHC in install_deps.	2020-04-19 16:33:45 +02:00
Julian Ospald	5d94d0bf75	Also check for GHC and Cabal updates on start	2020-04-18 20:20:18 +02:00
Julian Ospald	72bcfa9270	Fix CI	2020-04-18 17:29:44 +02:00
Julian Ospald	fafff9dadd	Update FAQ	2020-04-18 16:57:51 +02:00
Julian Ospald	e3c20d53a8	Add changelog command This should be backwardscompatible with 0.0.1 json format. Also slightly change 'getTagged' to list the latest version with a tag, not the oldest.	2020-04-18 15:06:22 +02:00
Julian Ospald	8b7dc68491	Fix ChangeLog date	2020-04-18 15:04:39 +02:00
Julian Ospald	7742fe08b5	Improve help messages	2020-04-17 22:58:15 +02:00
Julian Ospald	a773da037c	On second thought...	2020-04-17 20:50:23 +02:00
Julian Ospald	dfeb814dcc	Formatting	2020-04-17 18:57:58 +02:00
Julian Ospald	0623c7b1b1	Improve error reporting	2020-04-17 18:57:58 +02:00
Julian Ospald	62005f83a4	Improve debug info	2020-04-17 18:57:58 +02:00
Julian Ospald	eaafd77a7e	Add --version and --numeric-version	2020-04-17 18:57:58 +02:00
Julian Ospald	9d9e415a09	Remove use of unsafe decodeUtf8	2020-04-17 09:30:45 +02:00
Julian Ospald	6c1ae585b7	Indicate removal of tmpdir after failed build	2020-04-17 09:29:31 +02:00
Julian Ospald	793aad7b6c	Fix ghc-make when files are in PATH Fixes #11	2020-04-16 23:15:21 +02:00
Julian Ospald	fd7807a66e	Add 0.1.4 downloads	2020-04-16 23:14:27 +02:00