From d30d2ac8a5c52cb022d380b4af4212fb75d80d8c Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 28 Jul 2020 20:55:00 +0200
Subject: [PATCH 01/19] Add cabal-install-3.4.0.0-rc1

---
 app/ghcup-gen/Validate.hs | 1 +
 app/ghcup/BrickMain.hs    | 2 ++
 app/ghcup/Main.hs         | 1 +
 lib/GHCup/Types.hs        | 1 +
 lib/GHCup/Types/JSON.hs   | 2 ++
 5 files changed, 7 insertions(+)

diff --git a/app/ghcup-gen/Validate.hs b/app/ghcup-gen/Validate.hs
index bd1ee0e..4dc214f 100644
--- a/app/ghcup-gen/Validate.hs
+++ b/app/ghcup-gen/Validate.hs
@@ -111,6 +111,7 @@ validate dls = do
    where
     isUniqueTag Latest         = True
     isUniqueTag Recommended    = True
+    isUniqueTag Prerelease     = False
     isUniqueTag (Base       _) = False
     isUniqueTag (UnknownTag _) = False
 
diff --git a/app/ghcup/BrickMain.hs b/app/ghcup/BrickMain.hs
index 67eea69..a40cb1b 100644
--- a/app/ghcup/BrickMain.hs
+++ b/app/ghcup/BrickMain.hs
@@ -112,6 +112,7 @@ ui AppState {..} =
 
   printTag Recommended        = withAttr "recommended" $ str "recommended"
   printTag Latest             = withAttr "latest" $ str "latest"
+  printTag Prerelease         = withAttr "prerelease" $ str "prerelease"
   printTag (Base       pvp'') = str ("base-" ++ T.unpack (prettyPVP pvp''))
   printTag (UnknownTag t    ) = str t
 
@@ -137,6 +138,7 @@ defaultAttributes = attrMap
   , ("installed"    , Vty.defAttr `Vty.withForeColor` Vty.green)
   , ("recommended"  , Vty.defAttr `Vty.withForeColor` Vty.green)
   , ("latest"       , Vty.defAttr `Vty.withForeColor` Vty.yellow)
+  , ("prerelease"   , Vty.defAttr `Vty.withForeColor` Vty.red)
   , ("help"         , Vty.defAttr `Vty.withStyle` Vty.italic)
   ]
 
diff --git a/app/ghcup/Main.hs b/app/ghcup/Main.hs
index 7cb639d..cf42698 100644
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
@@ -1422,6 +1422,7 @@ printListResult raw lr = do
  where
   printTag Recommended        = color' Green "recommended"
   printTag Latest             = color' Yellow "latest"
+  printTag Prerelease         = color' Red "prerelease"
   printTag (Base pvp'') = "base-" ++ T.unpack (prettyPVP pvp'')
   printTag (UnknownTag t    ) = t
   color' = case raw of
diff --git a/lib/GHCup/Types.hs b/lib/GHCup/Types.hs
index df6a8e5..070b2ec 100644
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -92,6 +92,7 @@ data VersionInfo = VersionInfo
 -- | A tag. These are currently attached to a version of a tool.
 data Tag = Latest
          | Recommended
+         | Prerelease
          | Base PVP
          | UnknownTag String  -- ^ used for upwardscompat
          deriving (Ord, Eq, Show) -- FIXME: manual JSON instance
diff --git a/lib/GHCup/Types/JSON.hs b/lib/GHCup/Types/JSON.hs
index c87e33d..c055894 100644
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -53,6 +53,7 @@ deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Requir
 instance ToJSON Tag where
   toJSON Latest             = String "Latest"
   toJSON Recommended        = String "Recommended"
+  toJSON Prerelease         = String "Prerelease"
   toJSON (Base       pvp'') = String ("base-" <> prettyPVP pvp'')
   toJSON (UnknownTag x    ) = String (T.pack x)
 
@@ -60,6 +61,7 @@ instance FromJSON Tag where
   parseJSON = withText "Tag" $ \t -> case T.unpack t of
     "Latest"                             -> pure Latest
     "Recommended"                        -> pure Recommended
+    "Prerelease"                         -> pure Prerelease
     ('b' : 'a' : 's' : 'e' : '-' : ver') -> case pvp (T.pack ver') of
       Right x -> pure $ Base x
       Left  e -> fail . show $ e

From af811f3dbc950149191c81ea21bd10adbc3743dc Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 28 Jul 2020 21:40:26 +0200
Subject: [PATCH 02/19] `nub` result in getInstalledCabals

---
 lib/GHCup/Utils.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 0f04867..052a057 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -245,7 +245,7 @@ getInstalledCabals = do
     Just (Left  _) -> pure $ Left f
     Nothing        -> pure $ Left f
   cs <- cabalSet -- for legacy cabal
-  pure $ maybe vs (\x -> Right x:vs) cs
+  pure $ maybe vs (\x -> nub $ Right x:vs) cs
 
 
 -- | Whether the given cabal version is installed.

From 86b0e4b31bc6233f43257b8222f7750c4f906de4 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 28 Jul 2020 21:44:25 +0200
Subject: [PATCH 03/19] Fix `cabalSet` for pre-release versions

---
 lib/GHCup/Utils.hs | 39 +++++++++++++++++++++++++++------------
 1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 052a057..9b9534d 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -259,18 +259,33 @@ cabalInstalled ver = do
 cabalSet :: (MonadIO m, MonadThrow m) => m (Maybe Version)
 cabalSet = do
   cabalbin <- (</> [rel|cabal|]) <$> liftIO ghcupBinDir
-  mc       <- liftIO $ handleIO (\_ -> pure Nothing) $ fmap Just $ executeOut
-    cabalbin
-    ["--numeric-version"]
-    Nothing
-  fmap join $ forM mc $ \c -> if
-             | not (B.null (_stdOut c))
-             , _exitCode c == ExitSuccess -> do
-                  let reportedVer = fst . B.spanEnd (== _lf) . _stdOut $ c
-                  case version $ decUTF8Safe reportedVer of
-                    Left  e -> throwM e
-                    Right r -> pure $ Just r
-             | otherwise -> pure Nothing
+  b        <- fmap (== SymbolicLink) $ liftIO $ getFileType cabalbin
+  if
+    | b -> do
+      liftIO $ handleIO' NoSuchThing (\_ -> pure $ Nothing) $ do
+        link <- readSymbolicLink $ toFilePath cabalbin
+        Just <$> linkVersion link
+    | otherwise -> do -- legacy behavior
+      mc <- liftIO $ handleIO (\_ -> pure Nothing) $ fmap Just $ executeOut
+        cabalbin
+        ["--numeric-version"]
+        Nothing
+      fmap join $ forM mc $ \c -> if
+        | not (B.null (_stdOut c)), _exitCode c == ExitSuccess -> do
+          let reportedVer = fst . B.spanEnd (== _lf) . _stdOut $ c
+          case version $ decUTF8Safe reportedVer of
+            Left  e -> throwM e
+            Right r -> pure $ Just r
+        | otherwise -> pure Nothing
+ where
+  linkVersion :: MonadThrow m => ByteString -> m Version
+  linkVersion bs = do
+    t <- throwEither $ E.decodeUtf8' bs
+    throwEither $ MP.parse parser "" t
+   where
+    parser =
+      MP.chunk "cabal-" *> version'
+
 
 
 

From 7d334c18f5edf68bbc9220cbabe92cda4a007dd7 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 28 Jul 2020 21:53:54 +0200
Subject: [PATCH 04/19] Don't stop TUI on subcommand failure

---
 app/ghcup/BrickMain.hs | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/app/ghcup/BrickMain.hs b/app/ghcup/BrickMain.hs
index a40cb1b..c3f526d 100644
--- a/app/ghcup/BrickMain.hs
+++ b/app/ghcup/BrickMain.hs
@@ -175,19 +175,18 @@ withIOAction :: (AppState -> (Int, ListResult) -> IO (Either String a))
 withIOAction action as = case listSelectedElement (lr as) of
   Nothing      -> continue as
   Just (ix, e) -> suspendAndResume $ do
-    r <- action as (ix, e)
-    case r of
-      Left  err -> throwIO $ userError err
-      Right _   -> do
-        apps <- (fmap . fmap)
-          (\AppState {..} -> AppState { lr = listMoveTo ix lr, .. })
-          $ getAppState Nothing (pfreq as)
-        case apps of
-          Right nas -> do
-            putStrLn "Press enter to continue"
-            _ <- getLine
-            pure nas
-          Left err -> throwIO $ userError err
+    action as (ix, e) >>= \case
+      Left  err -> putStrLn $ ("Error: " <> err)
+      Right _   -> putStrLn "Success"
+    apps <- (fmap . fmap)
+      (\AppState {..} -> AppState { lr = listMoveTo ix lr, .. })
+      $ getAppState Nothing (pfreq as)
+    case apps of
+      Right nas -> do
+        putStrLn "Press enter to continue"
+        _ <- getLine
+        pure nas
+      Left err -> throwIO $ userError err
 
 
 install' :: AppState -> (Int, ListResult) -> IO (Either String ())

From aac8f760adbc16857ff1042847f45d03c7e26c69 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Wed, 29 Jul 2020 01:43:00 +0200
Subject: [PATCH 05/19] Add xdg support wrt #39

---
 README.md                 | 11 +++++
 app/ghcup/Main.hs         | 16 ++++---
 bootstrap-haskell         | 39 +++++++++++------
 lib/GHCup.hs              |  6 +--
 lib/GHCup/Download.hs     |  2 +-
 lib/GHCup/Utils.hs        | 61 +++++++++++++++-----------
 lib/GHCup/Utils/Dirs.hs   | 90 ++++++++++++++++++++++++++++++++++++---
 lib/GHCup/Utils/File.hs   |  9 ++++
 lib/GHCup/Utils/Logger.hs |  2 +-
 9 files changed, 179 insertions(+), 57 deletions(-)

diff --git a/README.md b/README.md
index 1f6cfc2..a726d17 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@ Similar in scope to [rustup](https://github.com/rust-lang-nursery/rustup.rs), [p
      * [Manpages](#manpages)
      * [Shell-completion](#shell-completion)
      * [Cross support](#cross-support)
+     * [XDG support](#xdg-support)
    * [Design goals](#design-goals)
    * [How](#how)
    * [Known users](#known-users)
@@ -96,6 +97,16 @@ For distributions with non-standard locations of cross toolchain and
 libraries, this may need some tweaking of `build.mk` or configure args.
 See `ghcup compile ghc --help` for further information.
 
+### Cross support
+
+To enable XDG style directories, set the environment variable `GHCUP_USE_XDG_DIRS` to anything.
+
+Then you can control the locations via XDG environment variables as such:
+
+* `XDG_DATA_HOME`: GHCs will be unpacked in `ghcup/ghc` subdir
+* `XDG_CACHE_HOME`: logs and download files will be stored in `ghcup` subdir
+* `XDG_BIN_HOME`: binaries end up here (default: `~/.local/bin`)
+
 ## Design goals
 
 1. simplicity
diff --git a/app/ghcup/Main.hs b/app/ghcup/Main.hs
index cf42698..5fd5172 100644
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
@@ -903,9 +903,11 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
     >>= \opt@Options {..} -> do
           let settings@Settings{..} = toSettings opt
 
+          logsDir <- toFilePath <$> ghcupLogsDir
+
           -- create ~/.ghcup dir
           ghcdir <- ghcupBaseDir
-          createDirIfMissing newDirPerms ghcdir
+          createDirRecursive newDirPerms ghcdir
 
           -- logger interpreter
           logfile <- initGHCupFileLogging [rel|ghcup.log|]
@@ -1079,7 +1081,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                             case keepDirs of
                               Never -> runLogger ($(logError) [i|Build failed with #{e}|])
                               _ -> runLogger ($(logError) [i|Build failed with #{e}
-    Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
+    Check the logs at #{logsDir} and the build directory #{tmpdir} for more clues.
     Make sure to clean up #{tmpdir} afterwards.|])
                             pure $ ExitFailure 3
                           VLeft (V NoDownload) -> do
@@ -1092,7 +1094,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                           VLeft e -> do
                             runLogger $ do
                               $(logError) [i|#{e}|]
-                              $(logError) [i|Also check the logs in ~/.ghcup/logs|]
+                              $(logError) [i|Also check the logs in #{logsDir}|]
                             pure $ ExitFailure 3
 
 
@@ -1121,7 +1123,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                         VLeft e -> do
                           runLogger $ do
                             $(logError) [i|#{e}|]
-                            $(logError) [i|Also check the logs in ~/.ghcup/logs|]
+                            $(logError) [i|Also check the logs in #{logsDir}|]
                           pure $ ExitFailure 4
 
           let setGHC' SetOptions{..} =
@@ -1237,9 +1239,9 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                       VLeft (V (BuildFailed tmpdir e)) -> do
                         case keepDirs of
                           Never -> runLogger ($(logError) [i|Build failed with #{e}
-Check the logs at ~/.ghcup/logs|])
+Check the logs at #{logsDir}|])
                           _ -> runLogger ($(logError) [i|Build failed with #{e}
-Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
+Check the logs at #{logsDir} and the build directory #{tmpdir} for more clues.
 Make sure to clean up #{tmpdir} afterwards.|])
                         pure $ ExitFailure 9
                       VLeft e -> do
@@ -1261,7 +1263,7 @@ Make sure to clean up #{tmpdir} afterwards.|])
                         case keepDirs of
                           Never -> runLogger ($(logError) [i|Build failed with #{e}|])
                           _ -> runLogger ($(logError) [i|Build failed with #{e}
-Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
+Check the logs at #{logsDir} and the build directory #{tmpdir} for more clues.
 Make sure to clean up #{tmpdir} afterwards.|])
                         pure $ ExitFailure 10
                       VLeft e -> do
diff --git a/bootstrap-haskell b/bootstrap-haskell
index e968d29..7b0c8cc 100755
--- a/bootstrap-haskell
+++ b/bootstrap-haskell
@@ -4,6 +4,17 @@
 (
 
 : "${GHCUP_INSTALL_BASE_PREFIX:=$HOME}"
+
+export GHCUP_USE_XDG_DIRS
+
+if [ -n "${GHCUP_USE_XDG_DIRS}" ] ; then
+	GHCUP_DIR=${XDG_DATA_HOME:=$HOME/.local}/ghcup
+	GHCUP_BIN=${XDG_BIN_HOME:=$HOME/.local/bin}
+else
+	GHCUP_DIR=${GHCUP_INSTALL_BASE_PREFIX}/.ghcup
+	GHCUP_BIN=${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin
+fi
+
 : "${BOOTSTRAP_HASKELL_GHC_VERSION:=recommended}"
 : "${BOOTSTRAP_HASKELL_CABAL_VERSION:=recommended}"
 
@@ -83,15 +94,15 @@ download_ghcup() {
 			;;
     esac
 
-	edo curl -Lf "${_url}" > "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/bin/ghcup
+	edo curl -Lf "${_url}" > "${GHCUP_BIN}"/ghcup
 
-    edo chmod +x "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/bin/ghcup
+    edo chmod +x "${GHCUP_BIN}"/ghcup
 
-	cat <<-EOF > "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/env || die "Failed to create env file"
-		export PATH="\$HOME/.cabal/bin:\${GHCUP_INSTALL_BASE_PREFIX:=\$HOME}/.ghcup/bin:\$PATH"
+	cat <<-EOF > "${GHCUP_DIR}"/env || die "Failed to create env file"
+		export PATH="\$HOME/.cabal/bin:${GHCUP_BIN}:\$PATH"
 		EOF
 	# shellcheck disable=SC1090
-    edo . "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/env
+    edo . "${GHCUP_DIR}"/env
     eghcup upgrade
 
 	unset _plat _arch _url _ghver _base_url
@@ -106,8 +117,12 @@ echo "  * ghcup - The Haskell toolchain installer (for managing GHC/cabal versio
 echo "  * ghc   - The Glasgow Haskell Compiler"
 echo "  * cabal - The Cabal build tool"
 echo
-echo "ghcup installs only into the following directory, which can be removed anytime:"
-echo "  $GHCUP_INSTALL_BASE_PREFIX/.ghcup"
+if [ -z "${GHCUP_USE_XDG_DIRS}" ] ; then
+	echo "ghcup installs only into the following directory, which can be removed anytime:"
+	echo "  $GHCUP_INSTALL_BASE_PREFIX/.ghcup"
+else
+	echo "ghcup installs into XDG directories as long as 'GHCUP_USE_XDG_DIRS' is set"
+fi
 echo
 
 if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
@@ -119,7 +134,7 @@ if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
     read -r answer </dev/tty
 fi
 
-edo mkdir -p "${GHCUP_INSTALL_BASE_PREFIX}"/.ghcup/bin
+edo mkdir -p "${GHCUP_BIN}"
 
 if command -V "ghcup" >/dev/null 2>&1 ; then
     if [ -z "${BOOTSTRAP_HASKELL_NO_UPGRADE}" ] ; then
@@ -156,7 +171,7 @@ printf "\\033[0;35m%s\\033[0m\\n" ""
 
 if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
     echo "In order to run ghc and cabal, you need to adjust your PATH variable."
-    echo "You may want to source '$GHCUP_INSTALL_BASE_PREFIX/.ghcup/env' in your shell"
+    echo "You may want to source '$GHCUP_DIR/env' in your shell"
     echo "configuration to do so (e.g. ~/.bashrc)."
 
 	case $SHELL in
@@ -199,14 +214,14 @@ if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 					"") break ;;
 					fish)
 						echo "set -q GHCUP_INSTALL_BASE_PREFIX[1]; or set GHCUP_INSTALL_BASE_PREFIX \$HOME" >> "${GHCUP_PROFILE_FILE}"
-						echo "test -f \$GHCUP_INSTALL_BASE_PREFIX/.ghcup/env ; and set -gx PATH \$HOME/.cabal/bin \$GHCUP_INSTALL_BASE_PREFIX/.ghcup/bin \$PATH" >> "${GHCUP_PROFILE_FILE}"
+						echo "test -f $GHCUP_DIR/env ; and set -gx PATH \$HOME/.cabal/bin $GHCUP_BIN/bin \$PATH" >> "${GHCUP_PROFILE_FILE}"
 						break ;;
 					*)
-						echo "[ -f \"\${GHCUP_INSTALL_BASE_PREFIX:=\$HOME}/.ghcup/env\" ] && source \"\${GHCUP_INSTALL_BASE_PREFIX:=\$HOME}/.ghcup/env\"" >> "${GHCUP_PROFILE_FILE}"
+						echo "[ -f \"${GHCUP_DIR}/env\" ] && source \"${GHCUP_DIR}/env\"" >> "${GHCUP_PROFILE_FILE}"
 						break ;;
 				esac
                 printf "\\033[0;35m%s\\033[0m\\n" "OK! ${GHCUP_PROFILE_FILE} has been modified. Restart your terminal for the changes to take effect,"
-                printf "\\033[0;35m%s\\033[0m\\n" "or type \"source ${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/env\" to apply them in your current terminal session."
+                printf "\\033[0;35m%s\\033[0m\\n" "or type \"source ${GHCUP_DIR}/env\" to apply them in your current terminal session."
                 exit 0;;
             [Nn]*)
                 exit 0;;
diff --git a/lib/GHCup.hs b/lib/GHCup.hs
index 8c55626..d712e50 100644
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
@@ -270,7 +270,7 @@ installCabalBindist dlinfo ver (PlatformRequest {..}) = do
   installCabal' path inst = do
     lift $ $(logInfo) "Installing cabal"
     let cabalFile = [rel|cabal|]
-    liftIO $ createDirIfMissing newDirPerms inst
+    liftIO $ createDirRecursive newDirPerms inst
     destFileName <- lift $ parseRel (toFilePath cabalFile <> "-" <> verToBS ver)
     handleIO (throwE . CopyError . show) $ liftIO $ copyFile
       (path </> cabalFile)
@@ -360,7 +360,7 @@ setGHC ver sghc = do
 
     -- create symlink
     let fullF = bindir </> targetFile
-    let destL = ghcLinkDestination (toFilePath file) ver
+    destL <- ghcLinkDestination (toFilePath file) ver
     lift $ $(logDebug) [i|ln -s #{destL} #{toFilePath fullF}|]
     liftIO $ createSymlink fullF destL
 
@@ -631,7 +631,7 @@ rmCabalVer :: (MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
            => Version
            -> Excepts '[NotInstalled] m ()
 rmCabalVer ver = do
-  whenM (fmap not $ liftIO $ cabalInstalled ver) $ throwE (NotInstalled GHC (prettyVer ver))
+  whenM (fmap not $ liftIO $ cabalInstalled ver) $ throwE (NotInstalled Cabal (prettyVer ver))
 
   cSet      <- liftIO cabalSet
 
diff --git a/lib/GHCup/Download.hs b/lib/GHCup/Download.hs
index bf9f4f1..e06e6ed 100644
--- a/lib/GHCup/Download.hs
+++ b/lib/GHCup/Download.hs
@@ -226,7 +226,7 @@ getDownloads urlSource = do
           else -- access in less than 5 minutes, re-use file
                liftIO $ readFile json_file
       else do
-        liftIO $ createDirIfMissing newDirPerms cacheDir
+        liftIO $ createDirRecursive newDirPerms cacheDir
         getModTime >>= \case
           Just modTime -> dlWithMod modTime json_file
           Nothing -> do
diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 9b9534d..fb94e6c 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -97,11 +97,15 @@ import qualified Text.Megaparsec               as MP
 
 
 -- | The symlink destination of a ghc tool.
-ghcLinkDestination :: ByteString -- ^ the tool, such as 'ghc', 'haddock' etc.
+ghcLinkDestination :: (MonadThrow m, MonadIO m)
+                   => ByteString -- ^ the tool, such as 'ghc', 'haddock' etc.
                    -> GHCTargetVersion
-                   -> ByteString
-ghcLinkDestination tool ver =
-  "../ghc/" <> E.encodeUtf8 (prettyTVer ver) <> "/bin/" <> tool
+                   -> m ByteString
+ghcLinkDestination tool ver = do
+  t <- parseRel tool
+  bin <- liftIO ghcupBinDir
+  ghcd <- liftIO $ ghcupGHCDir ver
+  pure (relativeSymlink bin (ghcd </> [rel|bin|] </> t))
 
 
 -- | Removes the minor GHC symlinks, e.g. ghc-8.6.5.
@@ -201,25 +205,26 @@ ghcSet mtarget = do
   liftIO $ handleIO' NoSuchThing (\_ -> pure $ Nothing) $ do
     link <- readSymbolicLink $ toFilePath ghcBin
     Just <$> ghcLinkVersion link
+
+ghcLinkVersion :: MonadThrow m => ByteString -> m GHCTargetVersion
+ghcLinkVersion bs = do
+  t <- throwEither $ E.decodeUtf8' bs
+  throwEither $ MP.parse parser "ghcLinkVersion" t
  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 "/"
-        <* MP.takeRest
-        <* MP.eof
+  parser =
+      (do
+         _    <- parseUntil1 (MP.chunk "/ghc/")
+         _    <- MP.chunk "/ghc/"
+         r    <- parseUntil1 (MP.chunk "/")
+         rest <- MP.getInput
+         MP.setInput r
+         x <- ghcTargetVerP
+         MP.setInput rest
+         pure x
+       )
+      <* MP.chunk "/"
+      <* MP.takeRest
+      <* MP.eof
 
 
 -- | Get all installed GHCs by reading ~/.ghcup/ghc/<dir>.
@@ -256,15 +261,19 @@ cabalInstalled ver = do
 
 
 -- Return the currently set cabal version, if any.
-cabalSet :: (MonadIO m, MonadThrow m) => m (Maybe Version)
+cabalSet :: (MonadIO m, MonadThrow m, MonadCatch m) => m (Maybe Version)
 cabalSet = do
   cabalbin <- (</> [rel|cabal|]) <$> liftIO ghcupBinDir
-  b        <- fmap (== SymbolicLink) $ liftIO $ getFileType cabalbin
+  b        <- handleIO (\_ -> pure False) $ fmap (== SymbolicLink) $ liftIO $ getFileType cabalbin
   if
     | b -> do
       liftIO $ handleIO' NoSuchThing (\_ -> pure $ Nothing) $ do
-        link <- readSymbolicLink $ toFilePath cabalbin
-        Just <$> linkVersion link
+        broken <- isBrokenSymlink cabalbin
+        if broken
+          then pure Nothing
+          else do
+            link <- readSymbolicLink $ toFilePath cabalbin
+            Just <$> linkVersion link
     | otherwise -> do -- legacy behavior
       mc <- liftIO $ handleIO (\_ -> pure Nothing) $ fmap Just $ executeOut
         cabalbin
diff --git a/lib/GHCup/Utils/Dirs.hs b/lib/GHCup/Utils/Dirs.hs
index f3c0b12..dc9d4cf 100644
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -24,6 +24,7 @@ import           Control.Exception.Safe
 import           Control.Monad
 import           Control.Monad.Reader
 import           Control.Monad.Trans.Resource
+import           Data.ByteString                ( ByteString )
 import           Data.Maybe
 import           HPath
 import           HPath.IO
@@ -35,6 +36,7 @@ import           Prelude                 hiding ( abs
 import           System.Posix.Env.ByteString    ( getEnv
                                                 , getEnvDefault
                                                 )
+import           System.Posix.FilePath  hiding  ( (</>) )
 import           System.Posix.Temp.ByteString   ( mkdtemp )
 
 import qualified Data.ByteString.UTF8          as UTF8
@@ -51,12 +53,25 @@ import qualified Text.Megaparsec               as MP
 
 
 -- | ~/.ghcup by default
+--
+-- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_DATA_HOME/ghcup' as per xdg spec.
 ghcupBaseDir :: IO (Path Abs)
 ghcupBaseDir = do
-  bdir <- getEnv "GHCUP_INSTALL_BASE_PREFIX" >>= \case
-    Just r  -> parseAbs r
-    Nothing -> liftIO getHomeDirectory
-  pure (bdir </> [rel|.ghcup|])
+  xdg <- useXDG
+  if xdg
+    then do
+      bdir <- getEnv "XDG_DATA_HOME" >>= \case
+        Just r  -> parseAbs r
+        Nothing -> do
+          home <- liftIO getHomeDirectory
+          pure (home </> [rel|.local/share|])
+      pure (bdir </> [rel|ghcup|])
+    else do
+      bdir <- getEnv "GHCUP_INSTALL_BASE_PREFIX" >>= \case
+        Just r  -> parseAbs r
+        Nothing -> liftIO getHomeDirectory
+      pure (bdir </> [rel|.ghcup|])
 
 
 -- | ~/.ghcup/ghc by default.
@@ -82,14 +97,54 @@ parseGHCupGHCDir (toFilePath -> f) = do
   throwEither $ MP.parse ghcTargetVerP "" fp
 
 
+-- | If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_BIN_HOME' env var or defaults to '~/.local/bin'
+-- (which, sadly is not strictly xdg spec).
 ghcupBinDir :: IO (Path Abs)
-ghcupBinDir = ghcupBaseDir <&> (</> [rel|bin|])
+ghcupBinDir = do
+  xdg <- useXDG
+  if xdg
+    then do
+      getEnv "XDG_BIN_HOME" >>= \case
+        Just r  -> parseAbs r
+        Nothing -> do
+          home <- liftIO getHomeDirectory
+          pure (home </> [rel|.local/bin|])
+    else ghcupBaseDir <&> (</> [rel|bin|])
 
+-- | Defaults to '~/.ghcup/cache'.
+--
+-- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_CACHE_HOME/ghcup' as per xdg spec.
 ghcupCacheDir :: IO (Path Abs)
-ghcupCacheDir = ghcupBaseDir <&> (</> [rel|cache|])
+ghcupCacheDir = do
+  xdg <- useXDG
+  if xdg
+    then do
+      bdir <- getEnv "XDG_CACHE_HOME" >>= \case
+        Just r  -> parseAbs r
+        Nothing -> do
+          home <- liftIO getHomeDirectory
+          pure (home </> [rel|.cache|])
+      pure (bdir </> [rel|ghcup|])
+    else ghcupBaseDir <&> (</> [rel|cache|])
 
+-- | Defaults to '~/.ghcup/logs'.
+--
+-- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
+-- then uses 'XDG_CACHE_HOME/ghcup/logs' as per xdg spec.
 ghcupLogsDir :: IO (Path Abs)
-ghcupLogsDir = ghcupBaseDir <&> (</> [rel|logs|])
+ghcupLogsDir = do
+  xdg <- useXDG
+  if xdg
+    then do
+      bdir <- getEnv "XDG_CACHE_HOME" >>= \case
+        Just r  -> parseAbs r
+        Nothing -> do
+          home <- liftIO getHomeDirectory
+          pure (home </> [rel|.cache|])
+      pure (bdir </> [rel|ghcup/logs|])
+    else ghcupBaseDir <&> (</> [rel|logs|])
 
 
 mkGhcupTmpDir :: (MonadThrow m, MonadIO m) => m (Path Abs)
@@ -116,3 +171,24 @@ getHomeDirectory = do
     Nothing -> do
       h <- PU.homeDirectory <$> (PU.getEffectiveUserID >>= PU.getUserEntryForID)
       parseAbs $ UTF8.fromString h -- this is a guess
+
+
+useXDG :: IO Bool
+useXDG = isJust <$> getEnv "GHCUP_USE_XDG_DIRS"
+
+
+relativeSymlink :: Path Abs  -- ^ the path in which to create the symlink
+                -> Path Abs  -- ^ the symlink destination
+                -> ByteString
+relativeSymlink (toFilePath -> p1) (toFilePath -> p2) =
+  let d1            = splitDirectories p1
+      d2            = splitDirectories p2
+      common        = takeWhile (\(x, y) -> x == y) $ zip d1 d2
+      cPrefix       = drop (length common) d1
+  in  joinPath (replicate (length cPrefix) "..")
+        <> joinPath ("/" : (drop (length common) d2))
+
+
+
+
+
diff --git a/lib/GHCup/Utils/File.hs b/lib/GHCup/Utils/File.hs
index eec8362..706ccda 100644
--- a/lib/GHCup/Utils/File.hs
+++ b/lib/GHCup/Utils/File.hs
@@ -427,3 +427,12 @@ findFiles' path parser = do
                              Right p' -> isJust $ MP.parseMaybe parser p')
     $ dirContentsStream dirStream
   pure $ join $ fmap parseRel f
+
+
+isBrokenSymlink :: Path Abs -> IO Bool
+isBrokenSymlink p =
+  handleIO
+      (\e -> if ioeGetErrorType e == NoSuchThing then pure True else throwIO e)
+    $ do
+        _ <- canonicalizePath p
+        pure False
diff --git a/lib/GHCup/Utils/Logger.hs b/lib/GHCup/Utils/Logger.hs
index 45f49dc..0b7088f 100644
--- a/lib/GHCup/Utils/Logger.hs
+++ b/lib/GHCup/Utils/Logger.hs
@@ -65,7 +65,7 @@ initGHCupFileLogging :: Path Rel -> IO (Path Abs)
 initGHCupFileLogging context = do
   logs <- ghcupLogsDir
   let logfile = logs </> context
-  createDirIfMissing newDirPerms logs
+  createDirRecursive newDirPerms logs
   hideError doesNotExistErrorType $ deleteFile logfile
   createRegularFile newFilePerms logfile
   pure logfile

From 9050c9792a879d8d253c514ed9112f50025b9504 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Wed, 29 Jul 2020 21:07:05 +0200
Subject: [PATCH 06/19] Improve bootstrap-haskell

---
 bootstrap-haskell | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/bootstrap-haskell b/bootstrap-haskell
index 7b0c8cc..467a119 100755
--- a/bootstrap-haskell
+++ b/bootstrap-haskell
@@ -40,6 +40,22 @@ _eghcup() {
     fi
 }
 
+_done() {
+	echo
+    echo "All done!"
+	echo
+	echo "To start a simple repl, run:"
+	echo "  ghci"
+	echo
+	echo "To start a new haskell project in the current directory, run:"
+	echo "  cabal init --interactive"
+	echo
+	echo "To install other GHC versions, run:"
+	echo "  ghcup tui"
+
+	exit 0
+}
+
 download_ghcup() {
 	_plat="$(uname -s)"
 	_arch=$(uname -m)
@@ -113,15 +129,18 @@ echo
 echo "Welcome to Haskell!"
 echo
 echo "This script will download and install the following binaries:"
-echo "  * ghcup - The Haskell toolchain installer (for managing GHC/cabal versions)"
+echo "  * ghcup - The Haskell toolchain installer"
+echo "            (for managing GHC/cabal versions)"
 echo "  * ghc   - The Glasgow Haskell Compiler"
 echo "  * cabal - The Cabal build tool"
 echo
 if [ -z "${GHCUP_USE_XDG_DIRS}" ] ; then
-	echo "ghcup installs only into the following directory, which can be removed anytime:"
+	echo "ghcup installs only into the following directory,"
+    echo "which can be removed anytime:"
 	echo "  $GHCUP_INSTALL_BASE_PREFIX/.ghcup"
 else
-	echo "ghcup installs into XDG directories as long as 'GHCUP_USE_XDG_DIRS' is set"
+	echo "ghcup installs into XDG directories as long as"
+    echo "'GHCUP_USE_XDG_DIRS' is set."
 fi
 echo
 
@@ -189,13 +208,13 @@ if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 				GHCUP_PROFILE_FILE="$HOME/.zshrc"
 				MY_SHELL="zsh"
 			else
-				exit 0
+			    _done
 			fi
 			;;
 		*/fish) # login shell is fish
 			GHCUP_PROFILE_FILE="$HOME/.config/fish/config.fish"
 			MY_SHELL="fish" ;;
-		*) exit 0 ;;
+		*) _done ;;
 	esac
 
 
@@ -222,9 +241,10 @@ if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 				esac
                 printf "\\033[0;35m%s\\033[0m\\n" "OK! ${GHCUP_PROFILE_FILE} has been modified. Restart your terminal for the changes to take effect,"
                 printf "\\033[0;35m%s\\033[0m\\n" "or type \"source ${GHCUP_DIR}/env\" to apply them in your current terminal session."
-                exit 0;;
+				_done
+                ;;
             [Nn]*)
-                exit 0;;
+                _done ;;
             *)
                 echo "Please type YES or NO and press enter.";;
         esac

From b9d7d7d007a728cd09b9c9ad2fc5c43a553ae5ce Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Thu, 30 Jul 2020 20:04:02 +0200
Subject: [PATCH 07/19] Fix licences in module haddock

---
 lib/GHCup.hs                  | 2 +-
 lib/GHCup/Download.hs         | 2 +-
 lib/GHCup/Errors.hs           | 2 +-
 lib/GHCup/Platform.hs         | 2 +-
 lib/GHCup/Requirements.hs     | 2 +-
 lib/GHCup/Types.hs            | 2 +-
 lib/GHCup/Types/JSON.hs       | 2 +-
 lib/GHCup/Types/Optics.hs     | 2 +-
 lib/GHCup/Utils.hs            | 2 +-
 lib/GHCup/Utils/Dirs.hs       | 2 +-
 lib/GHCup/Utils/File.hs       | 2 +-
 lib/GHCup/Utils/Logger.hs     | 2 +-
 lib/GHCup/Utils/MegaParsec.hs | 2 +-
 lib/GHCup/Utils/Prelude.hs    | 2 +-
 lib/GHCup/Utils/String/QQ.hs  | 2 +-
 lib/GHCup/Utils/Version/QQ.hs | 2 +-
 lib/GHCup/Version.hs          | 2 +-
 17 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/lib/GHCup.hs b/lib/GHCup.hs
index d712e50..bdfacd5 100644
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
@@ -15,7 +15,7 @@
 Module      : GHCup
 Description : GHCup installation functions
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Download.hs b/lib/GHCup/Download.hs
index e06e6ed..45ff181 100644
--- a/lib/GHCup/Download.hs
+++ b/lib/GHCup/Download.hs
@@ -13,7 +13,7 @@
 Module      : GHCup.Download
 Description : Downloading
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Errors.hs b/lib/GHCup/Errors.hs
index 4108121..5f09bfb 100644
--- a/lib/GHCup/Errors.hs
+++ b/lib/GHCup/Errors.hs
@@ -7,7 +7,7 @@
 Module      : GHCup.Errors
 Description : GHCup error types
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Platform.hs b/lib/GHCup/Platform.hs
index 6f69eef..1fa8c14 100644
--- a/lib/GHCup/Platform.hs
+++ b/lib/GHCup/Platform.hs
@@ -10,7 +10,7 @@
 Module      : GHCup.Plaform
 Description : Retrieving platform information
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Requirements.hs b/lib/GHCup/Requirements.hs
index 24f4761..83753f8 100644
--- a/lib/GHCup/Requirements.hs
+++ b/lib/GHCup/Requirements.hs
@@ -4,7 +4,7 @@
 Module      : GHCup.Requirements
 Description : Requirements utilities
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Types.hs b/lib/GHCup/Types.hs
index 070b2ec..ed69f03 100644
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -6,7 +6,7 @@
 Module      : GHCup.Types
 Description : GHCup types
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Types/JSON.hs b/lib/GHCup/Types/JSON.hs
index c055894..1f27bee 100644
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -14,7 +14,7 @@
 Module      : GHCup.Types.JSON
 Description : GHCup JSON types/instances
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Types/Optics.hs b/lib/GHCup/Types/Optics.hs
index 5fb344e..2486175 100644
--- a/lib/GHCup/Types/Optics.hs
+++ b/lib/GHCup/Types/Optics.hs
@@ -4,7 +4,7 @@
 Module      : GHCup.Types.Optics
 Description : GHCup optics
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index fb94e6c..f251ab9 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -10,7 +10,7 @@
 Module      : GHCup.Utils
 Description : GHCup domain specific utilities
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/Dirs.hs b/lib/GHCup/Utils/Dirs.hs
index dc9d4cf..814fc6f 100644
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -6,7 +6,7 @@
 Module      : GHCup.Utils.Dirs
 Description : Definition of GHCup directories
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/File.hs b/lib/GHCup/Utils/File.hs
index 706ccda..be16bd5 100644
--- a/lib/GHCup/Utils/File.hs
+++ b/lib/GHCup/Utils/File.hs
@@ -7,7 +7,7 @@
 Module      : GHCup.Utils.File
 Description : File and unix APIs
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/Logger.hs b/lib/GHCup/Utils/Logger.hs
index 0b7088f..2e58cc1 100644
--- a/lib/GHCup/Utils/Logger.hs
+++ b/lib/GHCup/Utils/Logger.hs
@@ -4,7 +4,7 @@
 Module      : GHCup.Utils.Logger
 Description : logger definition
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/MegaParsec.hs b/lib/GHCup/Utils/MegaParsec.hs
index d652361..ac379fe 100644
--- a/lib/GHCup/Utils/MegaParsec.hs
+++ b/lib/GHCup/Utils/MegaParsec.hs
@@ -5,7 +5,7 @@
 Module      : GHCup.Utils.MegaParsec
 Description : MegaParsec utilities
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/Prelude.hs b/lib/GHCup/Utils/Prelude.hs
index 20fd896..6bd913b 100644
--- a/lib/GHCup/Utils/Prelude.hs
+++ b/lib/GHCup/Utils/Prelude.hs
@@ -12,7 +12,7 @@
 Module      : GHCup.Utils.Prelude
 Description : MegaParsec utilities
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/String/QQ.hs b/lib/GHCup/Utils/String/QQ.hs
index 6cff357..85f566f 100644
--- a/lib/GHCup/Utils/String/QQ.hs
+++ b/lib/GHCup/Utils/String/QQ.hs
@@ -4,7 +4,7 @@
 Module      : GHCup.Utils.String.QQ
 Description : String quasi quoters
 Copyright   : (c) Audrey Tang <audreyt@audreyt.org> 2019, Julian Ospald <hasufell@posteo.de> 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Utils/Version/QQ.hs b/lib/GHCup/Utils/Version/QQ.hs
index 663460e..73912cc 100644
--- a/lib/GHCup/Utils/Version/QQ.hs
+++ b/lib/GHCup/Utils/Version/QQ.hs
@@ -11,7 +11,7 @@
 Module      : GHCup.Utils.Version.QQ
 Description : Version quasi-quoters
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
diff --git a/lib/GHCup/Version.hs b/lib/GHCup/Version.hs
index 55a923e..24d4ad7 100644
--- a/lib/GHCup/Version.hs
+++ b/lib/GHCup/Version.hs
@@ -5,7 +5,7 @@
 Module      : GHCup.Version
 Description : Static version information
 Copyright   : (c) Julian Ospald, 2020
-License     : GPL-3
+License     : LGPL-3.0
 Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX

From 122c54b51e46a70949f3a37612d947850f80cf92 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Thu, 30 Jul 2020 20:04:37 +0200
Subject: [PATCH 08/19] Refactor

---
 lib/GHCup/Utils.hs | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index f251ab9..53b9523 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -376,17 +376,16 @@ unpackToDir dest av = do
 #if defined(TAR)
   let untar :: MonadIO m => BL.ByteString -> Excepts '[] m ()
       untar = liftIO . Tar.unpack (toFilePath dest) . Tar.read
+
+      rf :: MonadIO m => Path Abs -> Excepts '[] m BL.ByteString
+      rf = liftIO . readFile
 #else
   let untar :: MonadIO m => BL.ByteString -> Excepts '[ArchiveResult] m ()
       untar = lEM . liftIO . runArchiveM . unpackToDirLazy (T.unpack . decUTF8Safe . toFilePath $ dest)
-#endif
 
-#if defined(TAR)
-      rf :: MonadIO m => Path Abs -> Excepts '[] m BL.ByteString
-#else
       rf :: MonadIO m => Path Abs -> Excepts '[ArchiveResult] m BL.ByteString
-#endif
       rf = liftIO . readFile
+#endif
 
   -- extract, depending on file extension
   if

From 7163b77837a98105a5b3eac36b5f3d60fb547e8e Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Fri, 31 Jul 2020 20:10:40 +0200
Subject: [PATCH 09/19] Only query directories once

---
 lib/GHCup/Types.hs      | 13 +++++-
 lib/GHCup/Utils.hs      | 14 ++----
 lib/GHCup/Utils/Dirs.hs | 99 +++++++++++++++++++++++++++--------------
 3 files changed, 82 insertions(+), 44 deletions(-)

diff --git a/lib/GHCup/Types.hs b/lib/GHCup/Types.hs
index ed69f03..0a49cfc 100644
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -158,14 +158,25 @@ data URLSource = GHCupURL
 
 
 data Settings = Settings
-  { cache      :: Bool
+  { -- * set by user
+    cache      :: Bool
   , noVerify   :: Bool
   , keepDirs   :: KeepDirs
   , downloader :: Downloader
   , verbose    :: Bool
+
+    -- * set on app start
+  , dirs       :: Dirs
   }
   deriving Show
 
+data Dirs = Dirs
+  { baseDir  :: Path Abs
+  , binDir   :: Path Abs
+  , cacheDir :: Path Abs
+  , logsDir  :: Path Abs
+  }
+  deriving Show
 
 data KeepDirs = Always
               | Errors
diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 53b9523..8c02886 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -576,24 +576,18 @@ runBuildAction :: (Show (V e), MonadReader Settings m, MonadIO m, MonadMask m)
                -> Excepts '[BuildFailed] m a
 runBuildAction bdir instdir action = do
   Settings {..} <- lift ask
-  v <- flip
-      onException
-      (do
+  let exAction = do
         forM_ instdir $ \dir ->
           liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
         when (keepDirs == Never)
           $ liftIO
           $ hideError doesNotExistErrorType
           $ deleteDirRecursive bdir
-      )
+  v <-
+    flip onException exAction
     $ catchAllE
         (\es -> do
-          forM_ instdir $ \dir ->
-            liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
-          when (keepDirs == Never)
-            $ liftIO
-            $ hideError doesNotExistErrorType
-            $ deleteDirRecursive bdir
+          exAction
           throwE (BuildFailed bdir es)
         )
     $ action
diff --git a/lib/GHCup/Utils/Dirs.hs b/lib/GHCup/Utils/Dirs.hs
index 814fc6f..0e72cf8 100644
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE OverloadedStrings     #-}
+{-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE QuasiQuotes           #-}
 {-# LANGUAGE ViewPatterns          #-}
 
@@ -11,7 +12,16 @@ Maintainer  : hasufell@hasufell.de
 Stability   : experimental
 Portability : POSIX
 -}
-module GHCup.Utils.Dirs where
+module GHCup.Utils.Dirs
+  ( getDirs
+  , ghcupGHCBaseDir
+  , ghcupGHCDir
+  , parseGHCupGHCDir
+  , mkGhcupTmpDir
+  , withGHCupTmpDir
+  , relativeSymlink
+  )
+where
 
 
 import           GHCup.Types
@@ -36,7 +46,7 @@ import           Prelude                 hiding ( abs
 import           System.Posix.Env.ByteString    ( getEnv
                                                 , getEnvDefault
                                                 )
-import           System.Posix.FilePath  hiding  ( (</>) )
+import           System.Posix.FilePath   hiding ( (</>) )
 import           System.Posix.Temp.ByteString   ( mkdtemp )
 
 import qualified Data.ByteString.UTF8          as UTF8
@@ -47,9 +57,9 @@ import qualified Text.Megaparsec               as MP
 
 
 
-    -------------------------
-    --[ GHCup directories ]--
-    -------------------------
+    ------------------------------
+    --[ GHCup base directories ]--
+    ------------------------------
 
 
 -- | ~/.ghcup by default
@@ -74,29 +84,6 @@ ghcupBaseDir = do
       pure (bdir </> [rel|.ghcup|])
 
 
--- | ~/.ghcup/ghc by default.
-ghcupGHCBaseDir :: IO (Path Abs)
-ghcupGHCBaseDir = ghcupBaseDir <&> (</> [rel|ghc|])
-
-
--- | 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 $ 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
-
-
 -- | If 'GHCUP_USE_XDG_DIRS' is set (to anything),
 -- then uses 'XDG_BIN_HOME' env var or defaults to '~/.local/bin'
 -- (which, sadly is not strictly xdg spec).
@@ -112,6 +99,7 @@ ghcupBinDir = do
           pure (home </> [rel|.local/bin|])
     else ghcupBaseDir <&> (</> [rel|bin|])
 
+
 -- | Defaults to '~/.ghcup/cache'.
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
@@ -129,6 +117,7 @@ ghcupCacheDir = do
       pure (bdir </> [rel|ghcup|])
     else ghcupBaseDir <&> (</> [rel|cache|])
 
+
 -- | Defaults to '~/.ghcup/logs'.
 --
 -- If 'GHCUP_USE_XDG_DIRS' is set (to anything),
@@ -147,6 +136,49 @@ ghcupLogsDir = do
     else ghcupBaseDir <&> (</> [rel|logs|])
 
 
+getDirs :: IO Dirs
+getDirs = do
+  baseDir  <- ghcupBaseDir
+  binDir   <- ghcupBinDir
+  cacheDir <- ghcupCacheDir
+  logsDir  <- ghcupLogsDir
+  pure Dirs { .. }
+
+
+
+    -------------------------
+    --[ GHCup directories ]--
+    -------------------------
+
+
+-- | ~/.ghcup/ghc by default.
+ghcupGHCBaseDir :: (MonadReader Settings m) => m (Path Abs)
+ghcupGHCBaseDir = do
+  Settings {..} <- ask
+  pure (baseDir dirs </> [rel|ghc|])
+
+
+-- | Gets '~/.ghcup/ghc/<ghcupGHCDir>'.
+-- The dir may be of the form
+--   * armv7-unknown-linux-gnueabihf-8.8.3
+--   * 8.8.4
+ghcupGHCDir :: (MonadReader Settings m, MonadThrow m)
+            => GHCTargetVersion
+            -> m (Path Abs)
+ghcupGHCDir ver = do
+  Settings {..} <- ask
+  ghcbasedir    <- ghcupGHCBaseDir
+  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
+
+
 mkGhcupTmpDir :: (MonadThrow m, MonadIO m) => m (Path Abs)
 mkGhcupTmpDir = do
   tmpdir <- liftIO $ getEnvDefault "TMPDIR" "/tmp"
@@ -158,6 +190,8 @@ withGHCupTmpDir :: (MonadResource m, MonadThrow m, MonadIO m) => m (Path Abs)
 withGHCupTmpDir = snd <$> allocate mkGhcupTmpDir deleteDirRecursive
 
 
+
+
     --------------
     --[ Others ]--
     --------------
@@ -181,14 +215,13 @@ relativeSymlink :: Path Abs  -- ^ the path in which to create the symlink
                 -> Path Abs  -- ^ the symlink destination
                 -> ByteString
 relativeSymlink (toFilePath -> p1) (toFilePath -> p2) =
-  let d1            = splitDirectories p1
-      d2            = splitDirectories p2
-      common        = takeWhile (\(x, y) -> x == y) $ zip d1 d2
-      cPrefix       = drop (length common) d1
+  let d1      = splitDirectories p1
+      d2      = splitDirectories p2
+      common  = takeWhile (\(x, y) -> x == y) $ zip d1 d2
+      cPrefix = drop (length common) d1
   in  joinPath (replicate (length cPrefix) "..")
         <> joinPath ("/" : (drop (length common) d2))
 
 
 
 
-

From cafedd73a2fbabb5e87850613bb8b91e17c9efac Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Wed, 5 Aug 2020 21:50:39 +0200
Subject: [PATCH 10/19] Use Settings to avoid querying dirs every time

---
 app/ghcup-gen/Validate.hs |   4 +-
 app/ghcup/BrickMain.hs    |   7 ++-
 app/ghcup/Main.hs         |  28 +++++----
 lib/GHCup.hs              | 119 ++++++++++++++++++++------------------
 lib/GHCup/Download.hs     |  10 ++--
 lib/GHCup/Types.hs        |   4 +-
 lib/GHCup/Utils.hs        |  72 ++++++++++++-----------
 lib/GHCup/Utils/File.hs   |   6 +-
 lib/GHCup/Utils/Logger.hs |  20 ++++---
 9 files changed, 140 insertions(+), 130 deletions(-)

diff --git a/app/ghcup-gen/Validate.hs b/app/ghcup-gen/Validate.hs
index 4dc214f..cec2130 100644
--- a/app/ghcup-gen/Validate.hs
+++ b/app/ghcup-gen/Validate.hs
@@ -7,6 +7,7 @@ module Validate where
 import           GHCup
 import           GHCup.Download
 import           GHCup.Types
+import           GHCup.Utils.Dirs
 import           GHCup.Utils.Logger
 
 import           Control.Exception.Safe
@@ -180,7 +181,8 @@ validateTarballs dls = do
 
  where
   downloadAll dli = do
-    let settings = Settings True False Never Curl False
+    dirs <- liftIO getDirs
+    let settings = Settings True False Never Curl False dirs
     let runLogger = myLoggerT LoggerConfig { lcPrintDebug = True
                                            , colorOutter  = B.hPut stderr
                                            , rawOutter    = (\_ -> pure ())
diff --git a/app/ghcup/BrickMain.hs b/app/ghcup/BrickMain.hs
index c3f526d..f563ced 100644
--- a/app/ghcup/BrickMain.hs
+++ b/app/ghcup/BrickMain.hs
@@ -297,14 +297,15 @@ uri' = unsafePerformIO (newIORef Nothing)
 
 settings' :: IORef Settings
 {-# NOINLINE settings' #-}
-settings' = unsafePerformIO
-  (newIORef Settings { cache      = True
+settings' = unsafePerformIO $ do
+  dirs <- getDirs
+  newIORef Settings { cache      = True
                      , noVerify   = False
                      , keepDirs   = Never
                      , downloader = Curl
                      , verbose    = False
+                     , ..
                      }
-  )
 
 
 logger' :: IORef LoggerConfig
diff --git a/app/ghcup/Main.hs b/app/ghcup/Main.hs
index 5fd5172..7464ae5 100644
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE CPP               #-}
 {-# LANGUAGE DataKinds         #-}
 {-# LANGUAGE TypeApplications  #-}
+{-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TemplateHaskell   #-}
 {-# LANGUAGE QuasiQuotes       #-}
@@ -818,14 +819,15 @@ bindistParser :: String -> Either String DownloadInfo
 bindistParser = eitherDecode . BLU.fromString
 
 
-toSettings :: Options -> Settings
-toSettings Options {..} =
+toSettings :: Options -> IO Settings
+toSettings Options {..} = do
   let cache      = optCache
       noVerify   = optNoVerify
       keepDirs   = optKeepDirs
       downloader = optsDownloader
       verbose    = optVerbose
-  in  Settings { .. }
+  dirs <- getDirs
+  pure $ Settings { .. }
 
 
 upgradeOptsP :: Parser UpgradeOpts
@@ -901,16 +903,13 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
             (footerDoc (Just $ text main_footer))
       )
     >>= \opt@Options {..} -> do
-          let settings@Settings{..} = toSettings opt
-
-          logsDir <- toFilePath <$> ghcupLogsDir
+          settings@Settings{dirs = Dirs{..}, ..} <- toSettings opt
 
           -- create ~/.ghcup dir
-          ghcdir <- ghcupBaseDir
-          createDirRecursive newDirPerms ghcdir
+          createDirRecursive newDirPerms baseDir
 
           -- logger interpreter
-          logfile <- initGHCupFileLogging [rel|ghcup.log|]
+          logfile <- flip runReaderT settings $ initGHCupFileLogging [rel|ghcup.log|]
           let loggerConfig = LoggerConfig
                 { lcPrintDebug = optVerbose
                 , colorOutter  = B.hPut stderr
@@ -956,12 +955,13 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
           let
             runSetCabal =
               runLogger
+                . flip runReaderT settings
                 . runE
                   @'[ NotInstalled
                     , TagNotFound
                     ]
 
-          let runListGHC = runLogger
+          let runListGHC = runLogger . flip runReaderT settings
 
           let runRm =
                 runLogger . flip runReaderT settings . runE @'[NotInstalled]
@@ -1054,7 +1054,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
 
           case optCommand of
             Upgrade _ _ -> pure ()
-            _ -> runLogger $ checkForUpdates dls pfreq
+            _ -> runLogger $ flip runReaderT settings $ checkForUpdates dls pfreq
 
 
 
@@ -1277,9 +1277,7 @@ Make sure to clean up #{tmpdir} afterwards.|])
                   p   <- parseAbs . E.encodeUtf8 . T.pack $ efp
                   pure $ Just p
                 (UpgradeAt p)   -> pure $ Just p
-                UpgradeGHCupDir -> do
-                  bdir <- liftIO $ ghcupBinDir
-                  pure (Just (bdir </> [rel|ghcup|]))
+                UpgradeGHCupDir -> pure (Just (binDir </> [rel|ghcup|]))
 
               (runUpgrade $ (liftE $ upgradeGHCup dls target force pfreq)) >>= \case
                 VRight v' -> do
@@ -1431,7 +1429,7 @@ printListResult raw lr = do
     True  -> flip const
     False -> color
 
-checkForUpdates :: (MonadCatch m, MonadLogger m, MonadThrow m, MonadIO m, MonadFail m, MonadLogger m)
+checkForUpdates :: (MonadReader Settings m, MonadCatch m, MonadLogger m, MonadThrow m, MonadIO m, MonadFail m, MonadLogger m)
                 => GHCupDownloads
                 -> PlatformRequest
                 -> m ()
diff --git a/lib/GHCup.hs b/lib/GHCup.hs
index bdfacd5..84b993e 100644
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
@@ -121,7 +121,7 @@ installGHCBindist :: ( MonadFail m
 installGHCBindist dlinfo ver (PlatformRequest {..}) = do
   let tver = (mkTVer ver)
   lift $ $(logDebug) [i|Requested to install GHC with #{ver}|]
-  whenM (liftIO $ ghcInstalled tver)
+  whenM (lift $ ghcInstalled tver)
     $ (throwE $ AlreadyInstalled GHC ver)
 
   -- download (or use cached version)
@@ -133,7 +133,7 @@ installGHCBindist dlinfo ver (PlatformRequest {..}) = do
   void $ liftIO $ darwinNotarization _rPlatform tmpUnpack
 
   -- prepare paths
-  ghcdir <- liftIO $ ghcupGHCDir tver
+  ghcdir <- lift $ ghcupGHCDir tver
 
   -- the subdir of the archive where we do the work
   let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)
@@ -230,14 +230,14 @@ installCabalBindist :: ( MonadMask m
 installCabalBindist dlinfo ver (PlatformRequest {..}) = do
   lift $ $(logDebug) [i|Requested to install cabal version #{ver}|]
 
-  bindir <- liftIO ghcupBinDir
+  Settings {dirs = Dirs {..}} <- lift ask
 
   whenM
-      (liftIO $ cabalInstalled ver >>= \a ->
+      (lift (cabalInstalled ver) >>= \a -> liftIO $
         handleIO (\_ -> pure False)
           $ fmap (\x -> a && isSymbolicLink x)
           -- ignore when the installation is a legacy cabal (binary, not symlink)
-          $ getSymbolicLinkStatus (toFilePath (bindir </> [rel|cabal|]))
+          $ getSymbolicLinkStatus (toFilePath (binDir </> [rel|cabal|]))
       )
     $ (throwE $ AlreadyInstalled Cabal ver)
 
@@ -252,10 +252,10 @@ installCabalBindist dlinfo ver (PlatformRequest {..}) = do
   -- the subdir of the archive where we do the work
   let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)
 
-  liftE $ installCabal' workdir bindir
+  liftE $ installCabal' workdir binDir
 
   -- create symlink if this is the latest version
-  cVers <- liftIO $ fmap rights $ getInstalledCabals
+  cVers <- lift $ fmap rights $ getInstalledCabals
   let lInstCabal = headMay . reverse . sort $ cVers
   when (maybe True (ver >=) lInstCabal) $ liftE $ setCabal ver
 
@@ -328,17 +328,17 @@ installCabalBin bDls ver pfreq = do
 --
 -- Additionally creates a @~\/.ghcup\/share -> ~\/.ghcup\/ghc\/\<ver\>\/share symlink@
 -- for 'SetGHCOnly' constructor.
-setGHC :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
+setGHC :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
        => GHCTargetVersion
        -> SetGHC
        -> Excepts '[NotInstalled] m GHCTargetVersion
 setGHC ver sghc = do
   let verBS = verToBS (_tvVersion ver)
-  ghcdir <- liftIO $ ghcupGHCDir ver
+  ghcdir <- lift $ ghcupGHCDir ver
 
   -- symlink destination
-  bindir <- liftIO $ ghcupBinDir
-  liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms bindir
+  Settings {dirs = Dirs {..}} <- lift ask
+  liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms binDir
 
   -- first delete the old symlinks (this fixes compatibility issues
   -- with old ghcup)
@@ -359,8 +359,8 @@ setGHC ver sghc = do
       SetGHC_XYZ -> parseRel (toFilePath file <> B.singleton _hyphen <> verBS)
 
     -- create symlink
-    let fullF = bindir </> targetFile
-    destL <- ghcLinkDestination (toFilePath file) ver
+    let fullF = binDir </> targetFile
+    destL <- lift $ ghcLinkDestination (toFilePath file) ver
     lift $ $(logDebug) [i|ln -s #{destL} #{toFilePath fullF}|]
     liftIO $ createSymlink fullF destL
 
@@ -371,12 +371,13 @@ setGHC ver sghc = do
 
  where
 
-  symlinkShareDir :: (MonadIO m, MonadLogger m)
+  symlinkShareDir :: (MonadReader Settings m, MonadIO m, MonadLogger m)
                   => Path Abs
                   -> ByteString
                   -> m ()
   symlinkShareDir ghcdir verBS = do
-    destdir <- liftIO $ ghcupBaseDir
+    Settings {dirs = Dirs {..}} <- ask
+    let destdir = baseDir
     case sghc of
       SetGHCOnly -> do
         let sharedir     = [rel|share|]
@@ -393,7 +394,7 @@ setGHC ver sghc = do
 
 
 -- | Set the @~\/.ghcup\/bin\/cabal@ symlink.
-setCabal :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
+setCabal :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
          => Version
          -> Excepts '[NotInstalled] m ()
 setCabal ver = do
@@ -401,14 +402,14 @@ setCabal ver = do
   targetFile <- parseRel ("cabal-" <> verBS)
 
   -- symlink destination
-  bindir     <- liftIO $ ghcupBinDir
-  liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms bindir
+  Settings {dirs = Dirs {..}} <- lift ask
+  liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms binDir
 
-  whenM (liftIO $ fmap not $ doesFileExist (bindir </> targetFile))
+  whenM (liftIO $ fmap not $ doesFileExist (binDir </> targetFile))
     $ throwE
     $ NotInstalled Cabal (prettyVer ver)
 
-  let cabalbin = bindir </> [rel|cabal|]
+  let cabalbin = binDir </> [rel|cabal|]
 
   -- delete old file (may be binary or symlink)
   lift $ $(logDebug) [i|rm -f #{toFilePath cabalbin}|]
@@ -467,6 +468,7 @@ listVersions :: ( MonadCatch m
                 , MonadThrow m
                 , MonadLogger m
                 , MonadIO m
+                , MonadReader Settings m
                 )
              => GHCupDownloads
              -> Maybe Tool
@@ -478,7 +480,7 @@ listVersions av lt criteria pfreq = do
     Just t -> do
       -- get versions from GHCupDownloads
       let avTools = availableToolVersions av t
-      lr <- filter' <$> forM (Map.toList avTools) (liftIO . toListResult t)
+      lr <- filter' <$> forM (Map.toList avTools) (toListResult t)
 
       case t of
         -- append stray GHCs
@@ -493,7 +495,7 @@ listVersions av lt criteria pfreq = do
       pure (ghcvers <> cabalvers <> ghcupvers)
 
  where
-  strayGHCs :: (MonadThrow m, MonadLogger m, MonadIO m)
+  strayGHCs :: (MonadReader Settings m, MonadThrow m, MonadLogger m, MonadIO m)
             => Map.Map Version [Tag]
             -> m [ListResult]
   strayGHCs avTools = do
@@ -504,7 +506,7 @@ listVersions av lt criteria pfreq = do
           Just _  -> pure Nothing
           Nothing -> do
             lSet    <- fmap (maybe False (\(GHCTargetVersion _ v ) -> v == _tvVersion)) $ ghcSet Nothing
-            fromSrc <- liftIO $ ghcSrcInstalled tver
+            fromSrc <- ghcSrcInstalled tver
             pure $ Just $ ListResult
               { lTool      = GHC
               , lVer       = _tvVersion
@@ -517,7 +519,7 @@ listVersions av lt criteria pfreq = do
               }
       Right tver@GHCTargetVersion{ .. } -> do
         lSet    <- fmap (maybe False (\(GHCTargetVersion _ v ) -> v == _tvVersion)) $ ghcSet _tvTarget
-        fromSrc <- liftIO $ ghcSrcInstalled tver
+        fromSrc <- ghcSrcInstalled tver
         pure $ Just $ ListResult
           { lTool      = GHC
           , lVer       = _tvVersion
@@ -534,7 +536,7 @@ listVersions av lt criteria pfreq = do
         pure Nothing
 
   -- NOTE: this are not cross ones, because no bindists
-  toListResult :: Tool -> (Version, [Tag]) -> IO ListResult
+  toListResult :: (MonadReader Settings m, MonadIO m, MonadCatch m) => Tool -> (Version, [Tag]) -> m ListResult
   toListResult t (v, tags) = case t of
     GHC -> do
       let lNoBindist = isLeft $ getDownloadInfo GHC v pfreq av
@@ -587,12 +589,12 @@ listVersions av lt criteria pfreq = do
 -- This may leave GHCup without a "set" version.
 -- Will try to fix the ghc-x.y symlink after removal (e.g. to an
 -- older version).
-rmGHCVer :: (MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
+rmGHCVer :: (MonadReader Settings m, MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
          => GHCTargetVersion
          -> Excepts '[NotInstalled] m ()
 rmGHCVer ver = do
-  isSetGHC <- fmap (maybe False (== ver)) $ ghcSet (_tvTarget ver)
-  dir      <- liftIO $ ghcupGHCDir ver
+  isSetGHC <- lift $ fmap (maybe False (== ver)) $ ghcSet (_tvTarget ver)
+  dir      <- lift $ ghcupGHCDir ver
   let d' = toFilePath dir
   exists <- liftIO $ doesDirectoryExist dir
 
@@ -615,36 +617,38 @@ rmGHCVer ver = do
       lift $ rmMajorSymlinks ver
       -- then fix them (e.g. with an earlier version)
       (mj, mi) <- getMajorMinorV (_tvVersion ver)
-      getGHCForMajor mj mi (_tvTarget ver) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+      lift (getGHCForMajor mj mi (_tvTarget ver)) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+
+      Settings {dirs = Dirs {..}} <- lift ask
 
       liftIO
-        $   ghcupBaseDir
-        >>= hideError doesNotExistErrorType
-        .   deleteFile
-        .   (</> [rel|share|])
+        $ hideError doesNotExistErrorType
+        $ deleteFile
+        $ (baseDir </> [rel|share|])
     else throwE (NotInstalled GHC (ver ^. tvVersion % to prettyVer))
 
 
 -- | Delete a cabal version. Will try to fix the @cabal@ symlink
 -- after removal (e.g. setting it to an older version).
-rmCabalVer :: (MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
+rmCabalVer :: (MonadReader Settings m, MonadThrow m, MonadLogger m, MonadIO m, MonadFail m, MonadCatch m)
            => Version
            -> Excepts '[NotInstalled] m ()
 rmCabalVer ver = do
-  whenM (fmap not $ liftIO $ cabalInstalled ver) $ throwE (NotInstalled Cabal (prettyVer ver))
+  whenM (lift $ fmap not $ cabalInstalled ver) $ throwE (NotInstalled Cabal (prettyVer ver))
 
-  cSet      <- liftIO cabalSet
+  cSet      <- lift $ cabalSet
+
+  Settings {dirs = Dirs {..}} <- lift ask
 
-  bindir    <- liftIO ghcupBinDir
   cabalFile <- lift $ parseRel ("cabal-" <> verToBS ver)
-  liftIO $ hideError doesNotExistErrorType $ deleteFile (bindir </> cabalFile)
+  liftIO $ hideError doesNotExistErrorType $ deleteFile (binDir </> cabalFile)
 
   when (maybe False (== ver) cSet) $ do
-    cVers <- liftIO $ fmap rights $ getInstalledCabals
+    cVers <- lift $ fmap rights $ getInstalledCabals
     case headMay . reverse . sort $ cVers of
       Just latestver -> setCabal latestver
       Nothing        -> liftIO $ hideError doesNotExistErrorType $ deleteFile
-        (bindir </> [rel|cabal|])
+        (binDir </> [rel|cabal|])
 
 
 
@@ -653,18 +657,19 @@ rmCabalVer ver = do
     ------------------
 
 
-getDebugInfo :: (MonadLogger m, MonadCatch m, MonadIO m)
+getDebugInfo :: (MonadReader Settings m, MonadLogger m, MonadCatch m, MonadIO m)
              => Excepts
                   '[NoCompatiblePlatform , NoCompatibleArch , DistroNotFound]
                   m
                   DebugInfo
 getDebugInfo = do
-  diBaseDir  <- liftIO $ ghcupBaseDir
-  diBinDir   <- liftIO $ ghcupBinDir
-  diGHCDir   <- liftIO $ ghcupGHCBaseDir
-  diCacheDir <- liftIO $ ghcupCacheDir
-  diArch     <- lE getArchitecture
-  diPlatform <- liftE $ getPlatform
+  Settings {dirs = Dirs {..}} <- lift ask
+  let diBaseDir  = baseDir
+  let diBinDir   = binDir
+  diGHCDir       <- lift ghcupGHCBaseDir
+  let diCacheDir = cacheDir
+  diArch         <- lE getArchitecture
+  diPlatform     <- liftE $ getPlatform
   pure $ DebugInfo { .. }
 
 
@@ -711,7 +716,7 @@ compileGHC :: ( MonadMask m
                 ()
 compileGHC dls tver bstrap jobs mbuildConfig patchdir aargs PlatformRequest {..} = do
   lift $ $(logDebug) [i|Requested to compile: #{tver} with #{bstrap}|]
-  whenM (liftIO $ ghcInstalled tver)
+  whenM (lift $ ghcInstalled tver)
         (throwE $ AlreadyInstalled GHC (tver ^. tvVersion))
 
   -- download source tarball
@@ -729,7 +734,7 @@ compileGHC dls tver bstrap jobs mbuildConfig patchdir aargs PlatformRequest {..}
     Right g    -> pure $ Right g
     Left  bver -> Left <$> parseRel ("ghc-" <> verToBS bver)
   let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
-  ghcdir <- liftIO $ ghcupGHCDir tver
+  ghcdir <- lift $ ghcupGHCDir tver
 
   liftE $ runBuildAction
     tmpUnpack
@@ -892,14 +897,14 @@ compileCabal :: ( MonadReader Settings m
 compileCabal dls tver bghc jobs patchdir PlatformRequest{..} = do
   lift $ $(logDebug) [i|Requested to compile: #{tver} with ghc-#{bghc}|]
 
-  bindir <- liftIO ghcupBinDir
+  Settings {dirs = Dirs {..}} <- lift ask
 
   whenM
-      (liftIO $ cabalInstalled tver >>= \a ->
+      (lift (cabalInstalled tver) >>= \a -> liftIO $
         handleIO (\_ -> pure False)
           $ fmap (\x -> a && isSymbolicLink x)
           -- ignore when the installation is a legacy cabal (binary, not symlink)
-          $ getSymbolicLinkStatus (toFilePath (bindir </> [rel|cabal|]))
+          $ getSymbolicLinkStatus (toFilePath (binDir </> [rel|cabal|]))
       )
     $ (throwE $ AlreadyInstalled Cabal tver)
 
@@ -919,11 +924,11 @@ compileCabal dls tver bghc jobs patchdir PlatformRequest{..} = do
   destFileName <- lift $ parseRel ("cabal-" <> verToBS tver)
   handleIO (throwE . CopyError . show) $ liftIO $ copyFile
     cbin
-    (bindir </> destFileName)
+    (binDir </> destFileName)
     Overwrite
 
   -- create symlink if this is the latest version
-  cVers <- liftIO $ fmap rights $ getInstalledCabals
+  cVers <- lift $ fmap rights $ getInstalledCabals
   let lInstCabal = headMay . reverse . sort $ cVers
   when (maybe True (tver >=) lInstCabal) $ liftE $ setCabal tver
 
@@ -1004,6 +1009,7 @@ upgradeGHCup :: ( MonadMask m
                   m
                   Version
 upgradeGHCup dls mtarget force pfreq = do
+  Settings {dirs = Dirs {..}} <- lift ask
   lift $ $(logInfo) [i|Upgrading GHCup...|]
   let latestVer = fromJust $ getLatest dls GHCup
   when (not force && (latestVer <= pvpToVersion ghcUpVer)) $ throwE NoUpdate
@@ -1016,7 +1022,6 @@ upgradeGHCup dls mtarget force pfreq = do
           `unionFileModes` ownerExecuteMode
           `unionFileModes` groupExecuteMode
           `unionFileModes` otherExecuteMode
-  binDir <- liftIO $ ghcupBinDir
   let fullDest = fromMaybe (binDir </> fn) mtarget
   liftIO $ hideError NoSuchThing $ deleteFile fullDest
   handleIO (throwE . CopyError . show) $ liftIO $ copyFile p
@@ -1034,7 +1039,7 @@ upgradeGHCup dls mtarget force pfreq = 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)
+postGHCInstall :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
                => GHCTargetVersion
                -> Excepts '[NotInstalled] m ()
 postGHCInstall ver@GHCTargetVersion{..} = do
@@ -1043,4 +1048,4 @@ postGHCInstall ver@GHCTargetVersion{..} = do
   -- Create ghc-x.y symlinks. This may not be the current
   -- version, create it regardless.
   (mj, mi) <- getMajorMinorV _tvVersion
-  getGHCForMajor mj mi _tvTarget >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+  lift (getGHCForMajor mj mi _tvTarget) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
diff --git a/lib/GHCup/Download.hs b/lib/GHCup/Download.hs
index 45ff181..ea59551 100644
--- a/lib/GHCup/Download.hs
+++ b/lib/GHCup/Download.hs
@@ -133,10 +133,10 @@ getDownloadsF urlSource = do
     (OwnSpec   _) -> liftE $ getDownloads urlSource
  where
   readFromCache = do
+    Settings {dirs = Dirs {..}} <- lift ask
     lift $ $(logWarn)
       [i|Could not get download info, trying cached version (this may not be recent!)|]
     let path = view pathL' ghcupURL
-    cacheDir  <- liftIO $ ghcupCacheDir
     yaml_file <- (cacheDir </>) <$> urlBaseName path
     bs        <-
       handleIO' NoSuchThing
@@ -200,8 +200,8 @@ getDownloads urlSource = do
                m1
                L.ByteString
   smartDl uri' = do
+    Settings {dirs = Dirs {..}} <- lift ask
     let path = view pathL' uri'
-    cacheDir  <- liftIO $ ghcupCacheDir
     json_file <- (cacheDir </>) <$> urlBaseName path
     e         <- liftIO $ doesFileExist json_file
     if e
@@ -392,15 +392,15 @@ downloadCached dli mfn = do
   cache <- lift getCache
   case cache of
     True -> do
-      cachedir <- liftIO $ ghcupCacheDir
+      Settings {dirs = Dirs {..}} <- lift ask
       fn       <- maybe (urlBaseName $ view (dlUri % pathL') dli) pure mfn
-      let cachfile = cachedir </> fn
+      let cachfile = cacheDir </> fn
       fileExists <- liftIO $ doesFileExist cachfile
       if
         | fileExists -> do
           liftE $ checkDigest dli cachfile
           pure $ cachfile
-        | otherwise -> liftE $ download dli cachedir mfn
+        | otherwise -> liftE $ download dli cacheDir mfn
     False -> do
       tmp <- lift withGHCupTmpDir
       liftE $ download dli tmp mfn
diff --git a/lib/GHCup/Types.hs b/lib/GHCup/Types.hs
index 0a49cfc..2e8374a 100644
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -158,14 +158,14 @@ data URLSource = GHCupURL
 
 
 data Settings = Settings
-  { -- * set by user
+  { -- set by user
     cache      :: Bool
   , noVerify   :: Bool
   , keepDirs   :: KeepDirs
   , downloader :: Downloader
   , verbose    :: Bool
 
-    -- * set on app start
+    -- set on app start
   , dirs       :: Dirs
   }
   deriving Show
diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 8c02886..445b187 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -97,24 +97,24 @@ import qualified Text.Megaparsec               as MP
 
 
 -- | The symlink destination of a ghc tool.
-ghcLinkDestination :: (MonadThrow m, MonadIO m)
+ghcLinkDestination :: (MonadReader Settings m, MonadThrow m, MonadIO m)
                    => ByteString -- ^ the tool, such as 'ghc', 'haddock' etc.
                    -> GHCTargetVersion
                    -> m ByteString
 ghcLinkDestination tool ver = do
+  Settings {dirs = Dirs {..}} <- ask
   t <- parseRel tool
-  bin <- liftIO ghcupBinDir
-  ghcd <- liftIO $ ghcupGHCDir ver
-  pure (relativeSymlink bin (ghcd </> [rel|bin|] </> t))
+  ghcd <- ghcupGHCDir ver
+  pure (relativeSymlink binDir (ghcd </> [rel|bin|] </> t))
 
 
 -- | Removes the minor GHC symlinks, e.g. ghc-8.6.5.
-rmMinorSymlinks :: (MonadIO m, MonadLogger m) => GHCTargetVersion -> m ()
+rmMinorSymlinks :: (MonadReader Settings m, MonadIO m, MonadLogger m) => GHCTargetVersion -> m ()
 rmMinorSymlinks GHCTargetVersion {..} = do
-  bindir <- liftIO $ ghcupBinDir
+  Settings {dirs = Dirs {..}} <- ask
 
   files  <- liftIO $ findFiles'
-    bindir
+    binDir
     (  maybe mempty (\x -> MP.chunk (x <> "-")) _tvTarget
     *> parseUntil1 (MP.chunk $ prettyVer _tvVersion)
     *> (MP.chunk $ prettyVer _tvVersion)
@@ -122,42 +122,41 @@ rmMinorSymlinks GHCTargetVersion {..} = do
     )
 
   forM_ files $ \f -> do
-    let fullF = (bindir </> f)
+    let fullF = (binDir </> f)
     $(logDebug) [i|rm -f #{toFilePath fullF}|]
     liftIO $ hideError doesNotExistErrorType $ deleteFile fullF
 
 
 -- | Removes the set ghc version for the given target, if any.
-rmPlain :: (MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
+rmPlain :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
   => Maybe Text -- ^ target
         -> Excepts '[NotInstalled] m ()
 rmPlain target = do
-  mtv <- ghcSet target
+  Settings {dirs = Dirs {..}} <- lift ask
+  mtv <- lift $ ghcSet target
   forM_ mtv $ \tv -> do
     files  <- liftE $ ghcToolFiles tv
-    bindir <- liftIO $ ghcupBinDir
     forM_ files $ \f -> do
-      let fullF = (bindir </> f)
+      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|])
+    let hdc_file = (binDir </> [rel|haddock-ghc|])
     lift $ $(logDebug) [i|rm -f #{toFilePath hdc_file}|]
     liftIO $ hideError doesNotExistErrorType $ deleteFile hdc_file
 
 
 -- | Remove the major GHC symlink, e.g. ghc-8.6.
-rmMajorSymlinks :: (MonadThrow m, MonadLogger m, MonadIO m)
+rmMajorSymlinks :: (MonadReader Settings m, MonadThrow m, MonadLogger m, MonadIO m)
                 => GHCTargetVersion
                 -> m ()
 rmMajorSymlinks GHCTargetVersion {..} = do
+  Settings {dirs = Dirs {..}} <- ask
   (mj, mi) <- getMajorMinorV _tvVersion
   let v' = intToText mj <> "." <> intToText mi
 
-  bindir <- liftIO ghcupBinDir
-
   files  <- liftIO $ findFiles'
-    bindir
+    binDir
     (  maybe mempty (\x -> MP.chunk (x <> "-")) _tvTarget
     *> parseUntil1 (MP.chunk v')
     *> MP.chunk v'
@@ -165,7 +164,7 @@ rmMajorSymlinks GHCTargetVersion {..} = do
     )
 
   forM_ files $ \f -> do
-    let fullF = (bindir </> f)
+    let fullF = (binDir </> f)
     $(logDebug) [i|rm -f #{toFilePath fullF}|]
     liftIO $ hideError doesNotExistErrorType $ deleteFile fullF
 
@@ -178,27 +177,28 @@ rmMajorSymlinks GHCTargetVersion {..} = do
 
 
 -- | Whethe the given GHC versin is installed.
-ghcInstalled :: GHCTargetVersion -> IO Bool
+ghcInstalled :: (MonadIO m, MonadReader Settings m, MonadThrow m) => GHCTargetVersion -> m Bool
 ghcInstalled ver = do
   ghcdir <- ghcupGHCDir ver
-  doesDirectoryExist ghcdir
+  liftIO $ doesDirectoryExist ghcdir
 
 
 -- | Whether the given GHC version is installed from source.
-ghcSrcInstalled :: GHCTargetVersion -> IO Bool
+ghcSrcInstalled :: (MonadIO m, MonadReader Settings m, MonadThrow m) => GHCTargetVersion -> m Bool
 ghcSrcInstalled ver = do
   ghcdir <- ghcupGHCDir ver
-  doesFileExist (ghcdir </> ghcUpSrcBuiltFile)
+  liftIO $ doesFileExist (ghcdir </> ghcUpSrcBuiltFile)
 
 
 -- | Whether the given GHC version is set as the current.
-ghcSet :: (MonadThrow m, MonadIO m)
+ghcSet :: (MonadReader Settings m, 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
+  Settings {dirs = Dirs {..}} <- ask
   ghc    <- parseRel $ E.encodeUtf8 (maybe "ghc" (<> "-ghc") mtarget)
-  ghcBin <- (</> ghc) <$> liftIO ghcupBinDir
+  let ghcBin = binDir </> ghc
 
   -- link destination is of the form ../ghc/<ver>/bin/ghc
   -- for old ghcup, it is ../ghc/<ver>/bin/ghc-<ver>
@@ -229,9 +229,9 @@ ghcLinkVersion bs = do
 
 -- | 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 :: (MonadReader Settings m, MonadIO m) => m [Either (Path Rel) GHCTargetVersion]
 getInstalledGHCs = do
-  ghcdir <- liftIO $ ghcupGHCBaseDir
+  ghcdir <- ghcupGHCBaseDir
   fs     <- liftIO $ hideErrorDef [NoSuchThing] [] $ getDirsFiles' ghcdir
   forM fs $ \f -> case parseGHCupGHCDir f of
     Right r -> pure $ Right r
@@ -239,11 +239,12 @@ getInstalledGHCs = do
 
 
 -- | Get all installed cabals, by matching on @~\/.ghcup\/bin/cabal-*@.
-getInstalledCabals :: IO [Either (Path Rel) Version]
+getInstalledCabals :: (MonadReader Settings m, MonadIO m, MonadCatch m)
+                   => m [Either (Path Rel) Version]
 getInstalledCabals = do
-  bindir <- liftIO $ ghcupBinDir
+  Settings {dirs = Dirs {..}} <- ask
   bins   <- liftIO $ handleIO (\_ -> pure []) $ findFiles
-    bindir
+    binDir
     (makeRegexOpts compExtended execBlank ([s|^cabal-.*$|] :: ByteString))
   vs <- forM bins $ \f -> case fmap version (fmap decUTF8Safe . B.stripPrefix "cabal-" . toFilePath $ f) of
     Just (Right r) -> pure $ Right r
@@ -254,16 +255,17 @@ getInstalledCabals = do
 
 
 -- | Whether the given cabal version is installed.
-cabalInstalled :: Version -> IO Bool
+cabalInstalled :: (MonadIO m, MonadReader Settings m, MonadCatch m) => Version -> m Bool
 cabalInstalled ver = do
   vers <- fmap rights $ getInstalledCabals
   pure $ elem ver $ vers
 
 
 -- Return the currently set cabal version, if any.
-cabalSet :: (MonadIO m, MonadThrow m, MonadCatch m) => m (Maybe Version)
+cabalSet :: (MonadReader Settings m, MonadIO m, MonadThrow m, MonadCatch m) => m (Maybe Version)
 cabalSet = do
-  cabalbin <- (</> [rel|cabal|]) <$> liftIO ghcupBinDir
+  Settings {dirs = Dirs {..}} <- ask
+  let cabalbin = binDir </> [rel|cabal|]
   b        <- handleIO (\_ -> pure False) $ fmap (== SymbolicLink) $ liftIO $ getFileType cabalbin
   if
     | b -> do
@@ -319,7 +321,7 @@ matchMajor v' major' minor' = case getMajorMinorV v' of
 
 -- | Get the latest installed full GHC version that satisfies X.Y.
 -- This reads `ghcupGHCBaseDir`.
-getGHCForMajor :: (MonadIO m, MonadThrow m)
+getGHCForMajor :: (MonadReader Settings m, MonadIO m, MonadThrow m)
                => Int        -- ^ major version component
                -> Int        -- ^ minor version component
                -> Maybe Text -- ^ the target triple
@@ -463,11 +465,11 @@ urlBaseName = parseRel . snd . B.breakEnd (== _slash) . urlDecode False
 -- Returns unversioned relative files, e.g.:
 --
 --   - @["hsc2hs","haddock","hpc","runhaskell","ghc","ghc-pkg","ghci","runghc","hp2ps"]@
-ghcToolFiles :: (MonadThrow m, MonadFail m, MonadIO m)
+ghcToolFiles :: (MonadReader Settings m, MonadThrow m, MonadFail m, MonadIO m)
              => GHCTargetVersion
              -> Excepts '[NotInstalled] m [Path Rel]
 ghcToolFiles ver = do
-  ghcdir <- liftIO $ ghcupGHCDir ver
+  ghcdir <- lift $ ghcupGHCDir ver
   let bindir = ghcdir </> [rel|bin|]
 
   -- fail if ghc is not installed
diff --git a/lib/GHCup/Utils/File.hs b/lib/GHCup/Utils/File.hs
index be16bd5..8ddae18 100644
--- a/lib/GHCup/Utils/File.hs
+++ b/lib/GHCup/Utils/File.hs
@@ -17,7 +17,6 @@ Some of these functions use sophisticated logging.
 -}
 module GHCup.Utils.File where
 
-import           GHCup.Utils.Dirs
 import           GHCup.Utils.Prelude
 import           GHCup.Types
 
@@ -123,9 +122,8 @@ execLogged :: (MonadReader Settings m, MonadIO m, MonadThrow m)
            -> Maybe [(ByteString, ByteString)] -- ^ optional environment
            -> m (Either ProcessError ())
 execLogged exe spath args lfile chdir env = do
-  Settings {..} <- ask
-  ldir          <- liftIO ghcupLogsDir
-  logfile       <- (ldir </>) <$> parseRel (toFilePath lfile <> ".log")
+  Settings {dirs = Dirs {..}, ..} <- ask
+  logfile       <- (logsDir </>) <$> parseRel (toFilePath lfile <> ".log")
   liftIO $ bracket (createFile (toFilePath logfile) newFilePerms)
                    closeFd
                    (action verbose)
diff --git a/lib/GHCup/Utils/Logger.hs b/lib/GHCup/Utils/Logger.hs
index 2e58cc1..0ff0004 100644
--- a/lib/GHCup/Utils/Logger.hs
+++ b/lib/GHCup/Utils/Logger.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE QuasiQuotes           #-}
+{-# LANGUAGE FlexibleContexts      #-}
 
 {-|
 Module      : GHCup.Utils.Logger
@@ -13,9 +14,11 @@ Here we define our main logger.
 -}
 module GHCup.Utils.Logger where
 
-import           GHCup.Utils
+import           GHCup.Types
 
 import           Control.Monad
+import           Control.Monad.IO.Class
+import           Control.Monad.Reader
 import           Control.Monad.Logger
 import           HPath
 import           HPath.IO
@@ -61,11 +64,12 @@ myLoggerT LoggerConfig {..} loggingt = runLoggingT loggingt mylogger
     rawOutter outr
 
 
-initGHCupFileLogging :: Path Rel -> IO (Path Abs)
+initGHCupFileLogging :: (MonadIO m, MonadReader Settings m) => Path Rel -> m (Path Abs)
 initGHCupFileLogging context = do
-  logs <- ghcupLogsDir
-  let logfile = logs </> context
-  createDirRecursive newDirPerms logs
-  hideError doesNotExistErrorType $ deleteFile logfile
-  createRegularFile newFilePerms logfile
-  pure logfile
+  Settings {dirs = Dirs {..}} <- ask
+  let logfile = logsDir </> context
+  liftIO $ do
+    createDirRecursive newDirPerms logsDir
+    hideError doesNotExistErrorType $ deleteFile logfile
+    createRegularFile newFilePerms logfile
+    pure logfile

From 5c45884f5ff7d1a4f2f100e96ef0fad6e7ad2a72 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Thu, 6 Aug 2020 13:28:20 +0200
Subject: [PATCH 11/19] Allow to specify regex for subdir

---
 .gitlab-ci.yml          |  2 +-
 app/ghcup/BrickMain.hs  |  4 +-
 app/ghcup/Main.hs       | 11 ++++-
 ghcup.cabal             |  4 ++
 lib/GHCup.hs            | 95 +++++++++++++++++++++++++++++------------
 lib/GHCup/Errors.hs     |  3 ++
 lib/GHCup/Types.hs      |  8 +++-
 lib/GHCup/Types/JSON.hs |  4 ++
 lib/GHCup/Utils.hs      | 24 +++++++++++
 lib/GHCup/Utils/Dirs.hs |  1 -
 10 files changed, 123 insertions(+), 33 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5495d6d..dcb7c51 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -57,7 +57,7 @@ variables:
   script:
     - ./.gitlab/script/ghcup_version.sh
   variables:
-    JSON_VERSION: "0.0.2"
+    JSON_VERSION: "0.0.3"
 
 .test_ghcup_version:linux:
   extends:
diff --git a/app/ghcup/BrickMain.hs b/app/ghcup/BrickMain.hs
index f563ced..b843976 100644
--- a/app/ghcup/BrickMain.hs
+++ b/app/ghcup/BrickMain.hs
@@ -214,7 +214,9 @@ install' AppState {..} (_, ListResult {..}) = do
             , TagNotFound
             , DigestError
             , DownloadFailed
-            , NoUpdate]
+            , NoUpdate
+            , TarDirDoesNotExist
+            ]
 
   (run $ do
       case lTool of
diff --git a/app/ghcup/Main.hs b/app/ghcup/Main.hs
index 7464ae5..9116ae8 100644
--- a/app/ghcup/Main.hs
+++ b/app/ghcup/Main.hs
@@ -404,7 +404,11 @@ installParser =
   installGHCFooter = [s|Discussion:
   Installs the specified GHC version (or a recommended default one) into
   a self-contained "~/.ghcup/ghc/<ghcver>" directory
-  and symlinks the ghc binaries to "~/.ghcup/bin/<binary>-<ghcver>".|]
+  and symlinks the ghc binaries to "~/.ghcup/bin/<binary>-<ghcver>".
+
+Examples:
+  # install GHC head
+  ghcup -n install ghc -u '{"dlHash": "", "dlSubdir": { "RegexDir": "ghc-.*"}, "dlUri": "https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27" }' head|]
 
 
 installOpts :: Parser InstallOptions
@@ -428,7 +432,7 @@ installOpts =
             <> long "url"
             <> metavar "BINDIST_URL"
             <> help
-                 "Provide DownloadInfo as json string, e.g.: '{ \"dlHash\": \"<sha256 hash>\", \"dlSubdir\": \"ghc-<ver>\", \"dlUri\": \"<uri>\" }'"
+                 "Provide DownloadInfo as json string, e.g.: '{ \"dlHash\": \"<sha256 hash>\", \"dlSubdir\": { \"RegexDir\": \"ghc-.*\"}, \"dlUri\": \"<uri>\" }'"
             )
           )
         )
@@ -940,6 +944,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                       , TagNotFound
                       , DigestError
                       , DownloadFailed
+                      , TarDirDoesNotExist
                       ]
 
           let
@@ -986,6 +991,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                       , NotFoundInPATH
                       , PatchFailed
                       , UnknownArchive
+                      , TarDirDoesNotExist
 #if !defined(TAR)
                       , ArchiveResult
 #endif
@@ -1005,6 +1011,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                       , NotInstalled
                       , PatchFailed
                       , UnknownArchive
+                      , TarDirDoesNotExist
 #if !defined(TAR)
                       , ArchiveResult
 #endif
diff --git a/ghcup.cabal b/ghcup.cabal
index cca484f..4f9c0cd 100644
--- a/ghcup.cabal
+++ b/ghcup.cabal
@@ -153,6 +153,9 @@ common safe
 common safe-exceptions
   build-depends: safe-exceptions >=0.1
 
+common split
+  build-depends: split >=0.2.3.4
+
 common streamly
   build-depends: streamly >=0.7.1
 
@@ -276,6 +279,7 @@ library
     , resourcet
     , safe
     , safe-exceptions
+    , split
     , streamly
     , streamly-posix
     , streamly-bytestring
diff --git a/lib/GHCup.hs b/lib/GHCup.hs
index 84b993e..0271bc2 100644
--- a/lib/GHCup.hs
+++ b/lib/GHCup.hs
@@ -112,6 +112,7 @@ installGHCBindist :: ( MonadFail m
                         , NoDownload
                         , NotInstalled
                         , UnknownArchive
+                        , TarDirDoesNotExist
 #if !defined(TAR)
                         , ArchiveResult
 #endif
@@ -136,7 +137,7 @@ installGHCBindist dlinfo ver (PlatformRequest {..}) = do
   ghcdir <- lift $ ghcupGHCDir tver
 
   -- the subdir of the archive where we do the work
-  let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)
+  workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
 
   liftE $ runBuildAction tmpUnpack (Just ghcdir) (installGHC' workdir ghcdir)
 
@@ -189,6 +190,7 @@ installGHCBin :: ( MonadFail m
                     , NoDownload
                     , NotInstalled
                     , UnknownArchive
+                    , TarDirDoesNotExist
 #if !defined(TAR)
                     , ArchiveResult
 #endif
@@ -221,6 +223,7 @@ installCabalBindist :: ( MonadMask m
                           , NoDownload
                           , NotInstalled
                           , UnknownArchive
+                          , TarDirDoesNotExist
 #if !defined(TAR)
                           , ArchiveResult
 #endif
@@ -250,7 +253,7 @@ installCabalBindist dlinfo ver (PlatformRequest {..}) = do
   void $ liftIO $ darwinNotarization _rPlatform tmpUnpack
 
   -- the subdir of the archive where we do the work
-  let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)
+  workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
 
   liftE $ installCabal' workdir binDir
 
@@ -300,6 +303,7 @@ installCabalBin :: ( MonadMask m
                       , NoDownload
                       , NotInstalled
                       , UnknownArchive
+                      , TarDirDoesNotExist
 #if !defined(TAR)
                       , ArchiveResult
 #endif
@@ -328,16 +332,22 @@ installCabalBin bDls ver pfreq = do
 --
 -- Additionally creates a @~\/.ghcup\/share -> ~\/.ghcup\/ghc\/\<ver\>\/share symlink@
 -- for 'SetGHCOnly' constructor.
-setGHC :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
+setGHC :: ( MonadReader Settings m
+          , MonadLogger m
+          , MonadThrow m
+          , MonadFail m
+          , MonadIO m
+          , MonadCatch m
+          )
        => GHCTargetVersion
        -> SetGHC
        -> Excepts '[NotInstalled] m GHCTargetVersion
 setGHC ver sghc = do
   let verBS = verToBS (_tvVersion ver)
-  ghcdir <- lift $ ghcupGHCDir ver
+  ghcdir                        <- lift $ ghcupGHCDir ver
 
   -- symlink destination
-  Settings {dirs = Dirs {..}} <- lift ask
+  Settings { dirs = Dirs {..} } <- lift ask
   liftIO $ hideError AlreadyExists $ createDirRecursive newDirPerms binDir
 
   -- first delete the old symlinks (this fixes compatibility issues
@@ -350,19 +360,26 @@ setGHC ver sghc = do
   -- for ghc tools (ghc, ghci, haddock, ...)
   verfiles <- ghcToolFiles ver
   forM_ verfiles $ \file -> do
-    targetFile <- case sghc of
-      SetGHCOnly -> pure file
+    mTargetFile <- case sghc of
+      SetGHCOnly -> pure $ Just file
       SetGHC_XY  -> do
-        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)
+        v' <-
+          handle
+            (\(e :: ParseError) -> lift $ $(logWarn) [i|#{e}|] >> pure Nothing)
+          $ fmap Just
+          $ getMajorMinorV (_tvVersion ver)
+        forM v' $ \(mj, mi) ->
+          let major' = E.encodeUtf8 $ intToText mj <> "." <> intToText mi
+          in  parseRel (toFilePath file <> B.singleton _hyphen <> major')
+      SetGHC_XYZ ->
+        fmap Just $ parseRel (toFilePath file <> B.singleton _hyphen <> verBS)
 
     -- create symlink
-    let fullF = binDir </> targetFile
-    destL <- lift $ ghcLinkDestination (toFilePath file) ver
-    lift $ $(logDebug) [i|ln -s #{destL} #{toFilePath fullF}|]
-    liftIO $ createSymlink fullF destL
+    forM mTargetFile $ \targetFile -> do
+      let fullF = binDir </> targetFile
+      destL <- lift $ ghcLinkDestination (toFilePath file) ver
+      lift $ $(logDebug) [i|ln -s #{destL} #{toFilePath fullF}|]
+      liftIO $ createSymlink fullF destL
 
   -- create symlink for share dir
   when (isNothing . _tvTarget $ ver) $ lift $ symlinkShareDir ghcdir verBS
@@ -376,7 +393,7 @@ setGHC ver sghc = do
                   -> ByteString
                   -> m ()
   symlinkShareDir ghcdir verBS = do
-    Settings {dirs = Dirs {..}} <- ask
+    Settings { dirs = Dirs {..} } <- ask
     let destdir = baseDir
     case sghc of
       SetGHCOnly -> do
@@ -589,7 +606,13 @@ listVersions av lt criteria pfreq = do
 -- This may leave GHCup without a "set" version.
 -- Will try to fix the ghc-x.y symlink after removal (e.g. to an
 -- older version).
-rmGHCVer :: (MonadReader Settings m, MonadThrow m, MonadLogger m, MonadIO m, MonadFail m)
+rmGHCVer :: ( MonadReader Settings m
+            , MonadThrow m
+            , MonadLogger m
+            , MonadIO m
+            , MonadFail m
+            , MonadCatch m
+            )
          => GHCTargetVersion
          -> Excepts '[NotInstalled] m ()
 rmGHCVer ver = do
@@ -614,12 +637,17 @@ rmGHCVer ver = do
 
       lift $ $(logInfo) [i|Removing/rewiring ghc-x.y symlinks|]
       -- first remove
-      lift $ rmMajorSymlinks ver
+      handle (\(_ :: ParseError) -> pure ()) $ lift $ rmMajorSymlinks ver
       -- then fix them (e.g. with an earlier version)
-      (mj, mi) <- getMajorMinorV (_tvVersion ver)
-      lift (getGHCForMajor mj mi (_tvTarget ver)) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+      v' <-
+        handle
+          (\(e :: ParseError) -> lift $ $(logWarn) [i|#{e}|] >> pure Nothing)
+        $ fmap Just
+        $ getMajorMinorV (_tvVersion ver)
+      forM_ v' $ \(mj, mi) -> lift (getGHCForMajor mj mi (_tvTarget ver))
+        >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
 
-      Settings {dirs = Dirs {..}} <- lift ask
+      Settings { dirs = Dirs {..} } <- lift ask
 
       liftIO
         $ hideError doesNotExistErrorType
@@ -708,6 +736,7 @@ compileGHC :: ( MonadMask m
                  , NotFoundInPATH
                  , PatchFailed
                  , UnknownArchive
+                 , TarDirDoesNotExist
 #if !defined(TAR)
                  , ArchiveResult
 #endif
@@ -733,7 +762,7 @@ compileGHC dls tver bstrap jobs mbuildConfig patchdir aargs PlatformRequest {..}
   bghc <- case bstrap of
     Right g    -> pure $ Right g
     Left  bver -> Left <$> parseRel ("ghc-" <> verToBS bver)
-  let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
+  workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlInfo)
   ghcdir <- lift $ ghcupGHCDir tver
 
   liftE $ runBuildAction
@@ -888,6 +917,7 @@ compileCabal :: ( MonadReader Settings m
                    , NotInstalled
                    , PatchFailed
                    , UnknownArchive
+                   , TarDirDoesNotExist
 #if !defined(TAR)
                    , ArchiveResult
 #endif
@@ -917,7 +947,7 @@ compileCabal dls tver bghc jobs patchdir PlatformRequest{..} = do
   liftE $ unpackToDir tmpUnpack dl
   void $ liftIO $ darwinNotarization _rPlatform tmpUnpack
 
-  let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
+  workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlInfo)
 
   cbin         <- liftE $ runBuildAction tmpUnpack Nothing (compile workdir)
 
@@ -1039,13 +1069,24 @@ upgradeGHCup dls mtarget force pfreq = do
 
 -- | Creates @ghc-x.y.z@ and @ghc-x.y@ symlinks. This is used for
 -- both installing from source and bindist.
-postGHCInstall :: (MonadReader Settings m, MonadLogger m, MonadThrow m, MonadFail m, MonadIO m)
+postGHCInstall :: ( MonadReader Settings m
+                  , MonadLogger m
+                  , MonadThrow m
+                  , MonadFail m
+                  , MonadIO m
+                  , MonadCatch m
+                  )
                => GHCTargetVersion
                -> Excepts '[NotInstalled] m ()
-postGHCInstall ver@GHCTargetVersion{..} = 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) <- getMajorMinorV _tvVersion
-  lift (getGHCForMajor mj mi _tvTarget) >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+  v' <-
+    handle (\(e :: ParseError) -> lift $ $(logWarn) [i|#{e}|] >> pure Nothing)
+    $ fmap Just
+    $ getMajorMinorV _tvVersion
+  forM_ v' $ \(mj, mi) -> lift (getGHCForMajor mj mi _tvTarget)
+    >>= mapM_ (\v -> liftE $ setGHC v SetGHC_XY)
+
diff --git a/lib/GHCup/Errors.hs b/lib/GHCup/Errors.hs
index 5f09bfb..fdf54b0 100644
--- a/lib/GHCup/Errors.hs
+++ b/lib/GHCup/Errors.hs
@@ -89,6 +89,9 @@ data JSONError = JSONDecodeError String
 data FileDoesNotExistError = FileDoesNotExistError ByteString
   deriving Show
 
+data TarDirDoesNotExist = TarDirDoesNotExist TarDir
+  deriving Show
+
 -- | File digest verification failed.
 data DigestError = DigestError Text Text
   deriving Show
diff --git a/lib/GHCup/Types.hs b/lib/GHCup/Types.hs
index 2e8374a..acdd482 100644
--- a/lib/GHCup/Types.hs
+++ b/lib/GHCup/Types.hs
@@ -137,7 +137,7 @@ data LinuxDistro = Debian
 -- to download, extract and install a tool.
 data DownloadInfo = DownloadInfo
   { _dlUri    :: URI
-  , _dlSubdir :: Maybe (Path Rel)
+  , _dlSubdir :: Maybe TarDir
   , _dlHash   :: Text
   }
   deriving (Eq, Show)
@@ -150,6 +150,12 @@ data DownloadInfo = DownloadInfo
     --------------
 
 
+-- | How to descend into a tar archive.
+data TarDir = RealDir (Path Rel)
+            | RegexDir String     -- ^ will be compiled to regex, the first match will "win"
+            deriving (Eq, Show)
+
+
 -- | Where to fetch GHCupDownloads from.
 data URLSource = GHCupURL
                | OwnSource URI
diff --git a/lib/GHCup/Types/JSON.hs b/lib/GHCup/Types/JSON.hs
index 1f27bee..1320c5e 100644
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -193,3 +193,7 @@ instance FromJSON (Path Rel) where
     case parseRel d of
       Right x -> pure x
       Left  e -> fail $ "Failure in HPath Rel (FromJSON)" <> show e
+
+
+deriveJSON defaultOptions{ sumEncoding = ObjectWithSingleField } ''TarDir
+
diff --git a/lib/GHCup/Utils.hs b/lib/GHCup/Utils.hs
index 445b187..e06e876 100644
--- a/lib/GHCup/Utils.hs
+++ b/lib/GHCup/Utils.hs
@@ -48,7 +48,9 @@ import           Control.Monad.Logger
 import           Control.Monad.Reader
 import           Data.ByteString                ( ByteString )
 import           Data.Either
+import           Data.Foldable
 import           Data.List
+import           Data.List.Split
 import           Data.Maybe
 import           Data.String.Interpolate
 import           Data.Text                      ( Text )
@@ -403,6 +405,28 @@ unpackToDir dest av = do
     | otherwise -> throwE $ UnknownArchive fn
 
 
+intoSubdir :: (MonadLogger m, MonadIO m, MonadThrow m, MonadCatch m)
+           => Path Abs       -- ^ unpacked tar dir
+           -> TarDir         -- ^ how to descend
+           -> Excepts '[TarDirDoesNotExist] m (Path Abs)
+intoSubdir bdir tardir = case tardir of
+  RealDir pr -> do
+    whenM (fmap not . liftIO . doesDirectoryExist $ (bdir </> pr))
+          (throwE $ TarDirDoesNotExist tardir)
+    pure (bdir </> pr)
+  RegexDir r -> do
+    let rs = splitOn "/" r
+    foldlM
+      (\y x ->
+        (fmap sort . handleIO (\_ -> pure []) . liftIO . findFiles y . regex $ x) >>= \case
+          []      -> throwE $ TarDirDoesNotExist tardir
+          (p : _) -> pure (y </> p)
+      )
+      bdir
+      rs
+    where regex = makeRegexOpts compIgnoreCase execBlank
+
+
 
 
     ------------
diff --git a/lib/GHCup/Utils/Dirs.hs b/lib/GHCup/Utils/Dirs.hs
index 0e72cf8..2704e42 100644
--- a/lib/GHCup/Utils/Dirs.hs
+++ b/lib/GHCup/Utils/Dirs.hs
@@ -166,7 +166,6 @@ ghcupGHCDir :: (MonadReader Settings m, MonadThrow m)
             => GHCTargetVersion
             -> m (Path Abs)
 ghcupGHCDir ver = do
-  Settings {..} <- ask
   ghcbasedir    <- ghcupGHCBaseDir
   verdir        <- parseRel $ E.encodeUtf8 (prettyTVer ver)
   pure (ghcbasedir </> verdir)

From d071a7e51ba35c612de67eaf10456210e9fab096 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Sun, 9 Aug 2020 10:33:32 +0200
Subject: [PATCH 12/19] Avoid duplicate edits to .bashrc etc

---
 bootstrap-haskell | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/bootstrap-haskell b/bootstrap-haskell
index 467a119..9afac86 100755
--- a/bootstrap-haskell
+++ b/bootstrap-haskell
@@ -232,11 +232,16 @@ if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 				case $MY_SHELL in
 					"") break ;;
 					fish)
-						echo "set -q GHCUP_INSTALL_BASE_PREFIX[1]; or set GHCUP_INSTALL_BASE_PREFIX \$HOME" >> "${GHCUP_PROFILE_FILE}"
-						echo "test -f $GHCUP_DIR/env ; and set -gx PATH \$HOME/.cabal/bin $GHCUP_BIN/bin \$PATH" >> "${GHCUP_PROFILE_FILE}"
+						if ! grep -q "ghcup-env" "${GHCUP_PROFILE_FILE}" ; then
+							echo "# ghcup-env" >> "${GHCUP_PROFILE_FILE}"
+							echo "set -q GHCUP_INSTALL_BASE_PREFIX[1]; or set GHCUP_INSTALL_BASE_PREFIX \$HOME" >> "${GHCUP_PROFILE_FILE}"
+							echo "test -f $GHCUP_DIR/env ; and set -gx PATH \$HOME/.cabal/bin $GHCUP_BIN/bin \$PATH" >> "${GHCUP_PROFILE_FILE}"
+						fi
 						break ;;
 					*)
-						echo "[ -f \"${GHCUP_DIR}/env\" ] && source \"${GHCUP_DIR}/env\"" >> "${GHCUP_PROFILE_FILE}"
+						if ! grep -q "ghcup-env" "${GHCUP_PROFILE_FILE}" ; then
+							echo "[ -f \"${GHCUP_DIR}/env\" ] && source \"${GHCUP_DIR}/env\" # ghcup-env" >> "${GHCUP_PROFILE_FILE}"
+						fi
 						break ;;
 				esac
                 printf "\\033[0;35m%s\\033[0m\\n" "OK! ${GHCUP_PROFILE_FILE} has been modified. Restart your terminal for the changes to take effect,"

From 47142dd376338bbac997caf315a3446e4193d879 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Sun, 9 Aug 2020 11:21:49 +0200
Subject: [PATCH 13/19] Test on 32bit

---
 .gitlab-ci.yml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index dcb7c51..9294a41 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -66,6 +66,13 @@ variables:
   before_script:
     - ./.gitlab/before_script/linux/install_deps.sh
 
+.test_ghcup_version:linux32:
+  extends:
+    - .test_ghcup_version
+    - .alpine:32bit
+  before_script:
+    - ./.gitlab/before_script/linux/alpine/install_deps.sh
+
 .test_ghcup_version:darwin:
   extends:
     - .test_ghcup_version
@@ -107,6 +114,13 @@ test:linux:latest:
     CABAL_VERSION: "3.2.0.0"
   allow_failure: true
 
+######## linux 32bit test ########
+
+test:linux:recommended:32bit:
+  extends: .test_ghcup_version:linux32
+  variables:
+    GHC_VERSION: "8.8.4"
+    CABAL_VERSION: "3.2.0.0"
 
 ######## darwin test ########
 

From 27b2d2ac7dcc6bf2ee6d4e422f0df8c86601eaa7 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Sun, 9 Aug 2020 11:22:12 +0200
Subject: [PATCH 14/19] Fix cabal.project for cabal-3.4

---
 cabal.project | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cabal.project b/cabal.project
index 4cd11a6..8412ed7 100644
--- a/cabal.project
+++ b/cabal.project
@@ -19,6 +19,6 @@ package ghcup
 constraints: http-io-streams -brotli
 
 package libarchive
-  flags: static
+  flags: +static
 
-allow-newer: base ghc-prim template-haskell
+allow-newer: base, ghc-prim, template-haskell

From dac64f5718561daf4f298f631097a7a0a02492b2 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Mon, 10 Aug 2020 22:22:48 +0200
Subject: [PATCH 15/19] Make TarDir backwardscompat

---
 ghcup-0.0.2.yaml        |  1 +
 lib/GHCup/Types/JSON.hs | 14 +++++++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/ghcup-0.0.2.yaml b/ghcup-0.0.2.yaml
index cbf278a..873de2f 100644
--- a/ghcup-0.0.2.yaml
+++ b/ghcup-0.0.2.yaml
@@ -1,3 +1,4 @@
+# !!! if you use RegexDir, then the version must be bumped !!!
 ---
 toolRequirements:
   GHC:
diff --git a/lib/GHCup/Types/JSON.hs b/lib/GHCup/Types/JSON.hs
index 1320c5e..c271a08 100644
--- a/lib/GHCup/Types/JSON.hs
+++ b/lib/GHCup/Types/JSON.hs
@@ -24,6 +24,7 @@ module GHCup.Types.JSON where
 import           GHCup.Types
 import           GHCup.Utils.Prelude
 
+import           Control.Applicative            ( (<|>) )
 import           Data.Aeson
 import           Data.Aeson.TH
 import           Data.Aeson.Types
@@ -195,5 +196,16 @@ instance FromJSON (Path Rel) where
       Left  e -> fail $ "Failure in HPath Rel (FromJSON)" <> show e
 
 
-deriveJSON defaultOptions{ sumEncoding = ObjectWithSingleField } ''TarDir
+instance ToJSON TarDir where
+  toJSON (RealDir  p) = toJSON p
+  toJSON (RegexDir r) = object ["RegexDir" .= r]
 
+instance FromJSON TarDir where
+  parseJSON v = realDir v <|> regexDir v
+   where
+    realDir = withText "TarDir" $ \t -> do
+      fp <- parseJSON (String t)
+      pure (RealDir fp)
+    regexDir = withObject "TarDir" $ \o -> do
+      r <- o .: "RegexDir"
+      pure $ RegexDir r

From 71cb75c1702bf7c6a7178950c92a118d448370f0 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Mon, 10 Aug 2020 22:25:23 +0200
Subject: [PATCH 16/19] Update .gitignore

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 505a0dc..7e8c03c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,3 +12,4 @@ tags
 TAGS
 /tmp/
 .entangled
+release/

From f63b2bf7441dd6077b49b8d609d7f060a184f9c3 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 11 Aug 2020 11:48:42 +0200
Subject: [PATCH 17/19] Fix CI

---
 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 9294a41..990daf2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -57,7 +57,7 @@ variables:
   script:
     - ./.gitlab/script/ghcup_version.sh
   variables:
-    JSON_VERSION: "0.0.3"
+    JSON_VERSION: "0.0.2"
 
 .test_ghcup_version:linux:
   extends:

From 6f1b8b4041f578429c26bd7c1f9086675c9f67c7 Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 11 Aug 2020 12:12:15 +0200
Subject: [PATCH 18/19] Fix build on 32bit

---
 .gitlab-ci.yml                  |  3 +++
 .gitlab/script/ghcup_version.sh | 12 +++++++++---
 ghcup-0.0.2.yaml                |  8 ++++++--
 ghcup.cabal                     |  2 +-
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 990daf2..d5c46ac 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -14,6 +14,7 @@ variables:
     - x86_64-linux
   variables:
     OS: "LINUX"
+    BIT: "64"
 
 .alpine:64bit:
   image: "alpine:edge"
@@ -36,12 +37,14 @@ variables:
     - x86_64-darwin
   variables:
     OS: "DARWIN"
+    BIT: "64"
 
 .freebsd:
   tags:
     - x86_64-freebsd
   variables:
     OS: "FREEBSD"
+    BIT: "64"
 
 .root_cleanup:
   after_script:
diff --git a/.gitlab/script/ghcup_version.sh b/.gitlab/script/ghcup_version.sh
index 1c410a8..baf3c55 100755
--- a/.gitlab/script/ghcup_version.sh
+++ b/.gitlab/script/ghcup_version.sh
@@ -22,14 +22,20 @@ ecabal update
 
 if [ "${OS}" = "DARWIN" ] ; then
 	ecabal build -w ghc-${GHC_VERSION} -ftui
+elif [ "${OS}" = "LINUX" ] ; then
+	if [ "${BIT}" = "32" ] ; then
+		ecabal build -w ghc-${GHC_VERSION} -finternal-downloader -ftui -ftar
+	else
+		ecabal build -w ghc-${GHC_VERSION} -finternal-downloader -ftui
+	fi
 else
 	ecabal build -w ghc-${GHC_VERSION} -finternal-downloader -ftui
 fi
 
-ecabal haddock
+ecabal haddock -w ghc-${GHC_VERSION} -ftar
 
-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')" .
+cp "$(ecabal new-exec -w ghc-${GHC_VERSION} --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup')" .
+cp "$(ecabal new-exec -w ghc-${GHC_VERSION} --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup-gen')" .
 
 cp ./ghcup "$CI_PROJECT_DIR"/.local/bin/ghcup
 cp ./ghcup-gen "$CI_PROJECT_DIR"/.local/bin/ghcup-gen
diff --git a/ghcup-0.0.2.yaml b/ghcup-0.0.2.yaml
index 873de2f..82eb2ca 100644
--- a/ghcup-0.0.2.yaml
+++ b/ghcup-0.0.2.yaml
@@ -1305,7 +1305,7 @@ ghcupDownloads:
       viArch:
         A_64:
           Linux_UnknownLinux:
-            unknown_versioning:
+            unknown_versioning: &ghcup-64
               dlUri: https://downloads.haskell.org/~ghcup/0.1.8/x86_64-linux-ghcup-0.1.8
               dlHash: 7ffcd4c3de156e895b648c75a36c762be2a4932883f3cd598f7a483c97d4a8a9
           Darwin:
@@ -1316,8 +1316,12 @@ ghcupDownloads:
             unknown_versioning:
               dlUri: https://downloads.haskell.org/~ghcup/0.1.8/x86_64-portbld-freebsd-ghcup-0.1.8
               dlHash: 442cdfe1b4525a327d9566e6270f909f7deba21c16dd4c7912537cf67e6cd521
+          Linux_Alpine:
+            unknown_versioning: *ghcup-64
         A_32:
           Linux_UnknownLinux:
-            unknown_versioning:
+            unknown_versioning: &ghcup-32
               dlUri: https://downloads.haskell.org/~ghcup/0.1.8/i386-linux-ghcup-0.1.8
               dlHash: 18ab162920cea662feae4b08f39d3879e9e416fde7b734afd8072c39d3c43cde
+          Linux_Alpine:
+            unknown_versioning: *ghcup-32
diff --git a/ghcup.cabal b/ghcup.cabal
index 4f9c0cd..5464209 100644
--- a/ghcup.cabal
+++ b/ghcup.cabal
@@ -112,7 +112,7 @@ common io-streams
   build-depends: io-streams >=1.5
 
 common libarchive
-  build-depends: libarchive >= 2.2.5.2
+  build-depends: libarchive >= 2.2.5.0
 
 common lzma
   build-depends: lzma >=0.0.0.3

From d2c5d4dfd941e66a2d0d518c8b2229a9c0a56cdd Mon Sep 17 00:00:00 2001
From: Julian Ospald <hasufell@posteo.de>
Date: Tue, 11 Aug 2020 20:21:45 +0200
Subject: [PATCH 19/19] Test that we're not missing GHCup alpine

---
 app/ghcup-gen/Validate.hs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/app/ghcup-gen/Validate.hs b/app/ghcup-gen/Validate.hs
index cec2130..9c4b7d0 100644
--- a/app/ghcup-gen/Validate.hs
+++ b/app/ghcup-gen/Validate.hs
@@ -9,6 +9,7 @@ import           GHCup.Download
 import           GHCup.Types
 import           GHCup.Utils.Dirs
 import           GHCup.Utils.Logger
+import           GHCup.Utils.Version.QQ
 
 import           Control.Exception.Safe
 import           Control.Monad
@@ -89,6 +90,15 @@ validate dls = do
     when ((not $ any (== FreeBSD) pspecs) && arch == A_64) $ lift $ $(logWarn)
       [i|FreeBSD missing for #{t} #{v'} #{arch}|]
 
+    -- alpine needs to be set explicitly, because
+    -- we cannot assume that "Linux UnknownLinux" runs on Alpine
+    -- (although it could be static)
+    when (not $ any (== Linux Alpine) pspecs) $
+      case t of
+        GHCup -> (lift $ $(logError) [i|Linux Alpine missing for #{t} #{v'} #{arch}|]) >> addError
+        Cabal | v > [vver|2.4.1.0|] -> (lift $ $(logError) [i|Linux Alpine missing for #{t} #{v'} #{arch}|]) >> addError
+        _     -> lift $ $(logWarn) [i|Linux Alpine missing for #{t} #{v'} #{arch}|]
+
   checkUniqueTags tool = do
     let allTags = join $ M.elems $ availableToolVersions dls tool
     let nonUnique =