Windows fix

Also fixes #360, because we resolve all tags/versions now
by default.

.gitlab-ci.yml

@@ -134,6 +134,7 @@ variables:
   extends:
     - .test_ghcup_version
     - .debian
+    - .root_cleanup
   before_script:
     - ./.gitlab/before_script/linux/install_deps.sh
 
@@ -141,6 +142,7 @@ variables:
   extends:
     - .test_ghcup_version
     - .alpine:32bit
+    - .root_cleanup
   before_script:
     - ./.gitlab/before_script/linux/alpine/install_deps.sh
 
@@ -148,6 +150,7 @@ variables:
   extends:
     - .test_ghcup_version
     - .linux:armv7
+    - .root_cleanup
   before_script:
     - ./.gitlab/before_script/linux/install_deps.sh
 
@@ -155,6 +158,7 @@ variables:
   extends:
     - .test_ghcup_version
     - .linux:aarch64
+    - .root_cleanup
   before_script:
     - ./.gitlab/before_script/linux/install_deps.sh
 

.gitlab/script/ghcup_version.sh

@@ -100,7 +100,7 @@ eghcup set ghc ${GHC_VERSION}
 eghcup install cabal ${CABAL_VERSION}
 [ `$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version` = "${CABAL_VERSION}" ]
 eghcup unset cabal
-"$GHCUP_BIN"/cabal --version && exit || echo yes
+"$GHCUP_BIN"/cabal --version && exit 1 || echo yes
 eghcup set cabal ${CABAL_VERSION}
 [ `$(eghcup whereis cabal ${CABAL_VERSION}) --numeric-version` = "${CABAL_VERSION}" ]
 [ `eghcup run --cabal ${CABAL_VERSION} -- cabal --numeric-version` = "${CABAL_VERSION}" ]
@@ -170,12 +170,14 @@ else
 	eghcup set ${GHC_VERSION}
 	[ "$(ghc --numeric-version)" = "${ghc_ver}" ]
 	eghcup unset ghc
-    "$GHCUP_BIN"/ghc --numeric-version && exit || echo yes
+    "$GHCUP_BIN"/ghc --numeric-version && exit 1 || echo yes
 	eghcup set ${GHC_VERSION}
 	eghcup --offline rm 8.10.3
 	[ "$(ghc --numeric-version)" = "${ghc_ver}" ]
 
 
+	ls -lah "$GHCUP_BIN"
+
 	if [ "${OS}" = "DARWIN" ] ; then
 		eghcup install hls
 		$(eghcup whereis hls) --version
@@ -187,12 +189,12 @@ else
 			eghcup install hls
 			haskell-language-server-wrapper --version
 			eghcup unset hls
-			"$GHCUP_BIN"/haskell-language-server-wrapper --version && exit || echo yes
+			"$GHCUP_BIN"/haskell-language-server-wrapper --version && exit 1 || echo yes
 
 			eghcup install stack
 			stack --version
-			eghcup unset hls
-			"$GHCUP_BIN"/stack --version && exit || echo yes
+			eghcup unset stack
+			"$GHCUP_BIN"/stack --version && exit 1 || echo yes
 		fi
 	fi
 fi
@@ -215,6 +217,8 @@ if [ "${OS}" = "LINUX" ] ; then
 	fi
 fi
 
+eghcup gc -c
+
 sha_sum() {
 	if [ "${OS}" = "FREEBSD" ] ; then
 		sha256 "$@"
@@ -262,6 +266,19 @@ if [ "${ARCH}" = "64" ] ; then
 		eghcup install hls -i "$(pwd)/isolated" 1.3.0
 		[ "$(isolated/haskell-language-server-wrapper --numeric-version)" = "1.3.0" ] ||
 			[ "$(isolated/haskell-language-server-wrapper --numeric-version)" = "1.3.0.0" ]
+
+		# test that isolated installs don't clean up target directory
+		cat <<EOF > "${GHCUP_BIN}/gmake"
+#!/bin/bash
+exit 1
+EOF
+		chmod +x "${GHCUP_BIN}/gmake"
+		mkdir isolated_tainted/
+		touch isolated_tainted/lol
+
+		! eghcup install ghc -i "$(pwd)/isolated_tainted" 8.10.5 --force
+		[ -e "$(pwd)/isolated_tainted/lol" ]
+		rm "${GHCUP_BIN}/gmake"
 	fi
 fi
 

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Revision history for ghcup
 
+## 0.1.17.8 -- 2022-05-11
+
+* Fix a serious (but hard to trigger) bug when combining `--isolate <DIR>` with `--force`, please make sure to upgrade or avoid `--force`
+* Fix HLS build not cleaning up properly on failed installations, fixes [#361](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/361)
+* Fix parsing of symlinks with multiple slashes, wrt [#353](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/353)
+* Re-enable upgrade functionality for all configurations wrt [MR #250](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/250) and [VSCode haskell issue #601](https://github.com/haskell/vscode-haskell/issues/601)
+* Fix `ghcup run --ghc 8.10` (for short versions) wrt [#360](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/360)
+    - this also introduces a `--quick` switch for `ghcup run`
+
 ## 0.1.17.7 -- 2022-04-21
 
 * Fix `ghcup run` on windows wrt [#345](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/345)

app/ghcup/BrickMain.hs

@@ -447,19 +447,19 @@ install' _ (_, ListResult {..}) = do
       case lTool of
         GHC   -> do
           let vi = getVersionInfo lVer GHC dls
-          liftE $ installGHCBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installGHCBin lVer GHCupInternal False $> (vi, dirs, ce)
         Cabal -> do
           let vi = getVersionInfo lVer Cabal dls
-          liftE $ installCabalBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installCabalBin lVer GHCupInternal False $> (vi, dirs, ce)
         GHCup -> do
           let vi = snd <$> getLatest dls GHCup
           liftE $ upgradeGHCup Nothing False False $> (vi, dirs, ce)
         HLS   -> do
           let vi = getVersionInfo lVer HLS dls
-          liftE $ installHLSBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installHLSBin lVer GHCupInternal False $> (vi, dirs, ce)
         Stack -> do
           let vi = getVersionInfo lVer Stack dls
-          liftE $ installStackBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installStackBin lVer GHCupInternal False $> (vi, dirs, ce)
     )
     >>= \case
           VRight (vi, Dirs{..}, Just ce) -> do

app/ghcup/GHCup/OptParse/Compile.hs

@@ -99,7 +99,7 @@ data HLSCompileOptions = HLSCompileOptions
     --[ Parsers ]--
     ---------------
 
-          
+
 compileP :: Parser CompileCommand
 compileP = subparser
   (  command
@@ -469,7 +469,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                     ghcs
                     jobs
                     ovewrwiteVer
-                    isolateDir
+                    (maybe GHCupInternal IsolateDir isolateDir)
                     cabalProject
                     cabalProjectLocal
                     patches
@@ -524,7 +524,7 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                     addConfArgs
                     buildFlavour
                     hadrian
-                    isolateDir
+                    (maybe GHCupInternal IsolateDir isolateDir)
         GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
         let vi = getVersionInfo (_tvVersion targetVer) GHC dls
         when setCompile $ void $ liftE $
@@ -541,11 +541,11 @@ compile compileCommand settings Dirs{..} runAppState runLogger = do
                 pure ExitSuccess
               VLeft (V (AlreadyInstalled _ v)) -> do
                 runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+                  "GHC ver " <> prettyVer v <> " already installed, remove it first to reinstall"
                 pure ExitSuccess
               VLeft (V (DirNotEmpty fp)) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                 pure $ ExitFailure 3
               VLeft err@(V (BuildFailed tmpdir _)) -> do
                 case keepDirs settings of

app/ghcup/GHCup/OptParse/Install.hs

@@ -210,13 +210,13 @@ installOpts tool =
            )
           )
     <*> switch
-          (short 'f' <> long "force" <> help "Force install")
+          (short 'f' <> long "force" <> help "Force install (THIS IS UNSAFE, only use it in Dockerfiles or CI)")
  where
   setDefault = case tool of
     Nothing  -> False
     Just GHC -> False
     Just _   -> True
-          
+
 
 
 
@@ -395,7 +395,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
          (v, vi) <- liftE $ fromVersion instVer GHC
          void $ liftE $ sequenceE (installGHCBin
                      (_tvVersion v)
-                     isolateDir
+                     (maybe GHCupInternal IsolateDir isolateDir)
                      forceInstall
                    )
                    $ when instSet $ when (isNothing isolateDir) $ void $ setGHC v SetGHCOnly Nothing
@@ -406,7 +406,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
            void $ liftE $ sequenceE (installGHCBindist
                        (DownloadInfo uri (Just $ RegexDir "ghc-.*") "")
                        (_tvVersion v)
-                       isolateDir
+                       (maybe GHCupInternal IsolateDir isolateDir)
                        forceInstall
                      )
                      $ when instSet $ when (isNothing isolateDir) $ void $ setGHC v SetGHCOnly Nothing
@@ -421,20 +421,20 @@ install installCommand settings getAppState' runLogger = case installCommand of
 
               VLeft (V (AlreadyInstalled _ v, ())) -> do
                 runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+                  "GHC ver " <> prettyVer v <> " already installed, remove it first to reinstall"
                 pure ExitSuccess
               VLeft (V (AlreadyInstalled _ v)) -> do
                 runLogger $ logWarn $
-                  "GHC ver " <> prettyVer v <> " already installed; if you really want to reinstall it, you may want to run 'ghcup install ghc --force " <> prettyVer v <> "'"
+                  "GHC ver " <> prettyVer v <> " already installed, remove it first to reinstall"
                 pure ExitSuccess
 
               VLeft (V (DirNotEmpty fp)) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                 pure $ ExitFailure 3
               VLeft (V (DirNotEmpty fp, ())) -> do
-                runLogger $ logWarn $
-                  "Install directory " <> T.pack fp <> " is not empty. Use 'ghcup install ghc --isolate " <> T.pack fp <> " --force ..." <> "' to install regardless."
+                runLogger $ logError $
+                  "Install directory " <> T.pack fp <> " is not empty."
                 pure $ ExitFailure 3
 
               VLeft err@(V (BuildFailed tmpdir _)) -> do
@@ -467,7 +467,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
          (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Cabal
          void $ liftE $ sequenceE (installCabalBin
                                     v
-                                    isolateDir
+                                    (maybe GHCupInternal IsolateDir isolateDir)
                                     forceInstall
                                   ) $ when instSet $ when (isNothing isolateDir) $ void $ setCabal v
          pure vi
@@ -477,7 +477,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
            void $ liftE $ sequenceE (installCabalBindist
                                       (DownloadInfo uri Nothing "")
                                       v
-                                      isolateDir
+                                      (maybe GHCupInternal IsolateDir isolateDir)
                                       forceInstall
                                     ) $ when instSet $ when (isNothing isolateDir) $ void $ setCabal v
            pure vi
@@ -518,7 +518,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
          (_tvVersion -> v, vi) <- liftE $ fromVersion instVer HLS
          void $ liftE $ sequenceE (installHLSBin
                                     v
-                                    isolateDir
+                                    (maybe GHCupInternal IsolateDir isolateDir)
                                     forceInstall
                                   ) $ when instSet $ when (isNothing isolateDir) $ void $ setHLS v SetHLSOnly Nothing
          pure vi
@@ -529,7 +529,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
            void $ liftE $ sequenceE (installHLSBindist
                                       (DownloadInfo uri (Just $ RegexDir "haskell-language-server-*") "")
                                       v
-                                      isolateDir
+                                      (maybe GHCupInternal IsolateDir isolateDir)
                                       forceInstall
                                     ) $ when instSet $ when (isNothing isolateDir) $ void $ setHLS v SetHLSOnly Nothing
            pure vi
@@ -578,7 +578,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
           (_tvVersion -> v, vi) <- liftE $ fromVersion instVer Stack
           void $ liftE $ sequenceE (installStackBin
                                      v
-                                     isolateDir
+                                     (maybe GHCupInternal IsolateDir isolateDir)
                                      forceInstall
                                    ) $ when instSet $ when (isNothing isolateDir) $ void $ setStack v
           pure vi
@@ -588,7 +588,7 @@ install installCommand settings getAppState' runLogger = case installCommand of
             void $ liftE $ sequenceE (installStackBindist
                                        (DownloadInfo uri Nothing "")
                                        v
-                                       isolateDir
+                                       (maybe GHCupInternal IsolateDir isolateDir)
                                        forceInstall
                                      ) $ when instSet $ when (isNothing isolateDir) $ void $ setStack v
             pure vi

app/ghcup/GHCup/OptParse/Run.hs

@@ -61,6 +61,7 @@ data RunOptions = RunOptions
   , runHLSVer     :: Maybe ToolVersion
   , runStackVer   :: Maybe ToolVersion
   , runBinDir     :: Maybe FilePath
+  , runQuick      :: Bool
   , runCOMMAND    :: [String]
   }
 
@@ -70,8 +71,8 @@ data RunOptions = RunOptions
     --[ Parsers ]--
     ---------------
 
-          
-    
+
+
 runOpts :: Parser RunOptions
 runOpts =
   RunOptions
@@ -121,6 +122,8 @@ runOpts =
            <> completer (bashCompleter "directory")
            )
           )
+    <*> switch
+          (short 'q' <> long "quick" <> help "Avoid any expensive work (such as downloads, version/tag resolution etc.). Disables --install.")
     <*> many (argument str (metavar "COMMAND" <> help "The command to run, with arguments (use longopts --). If omitted, just prints the created bin/ dir to stdout and exits."))
           
 
@@ -219,29 +222,15 @@ run :: forall m.
    -> (ReaderT LeanAppState m () -> m ())
    -> m ExitCode
 run RunOptions{..} runAppState leanAppstate runLogger = do
-   r <- if or (fmap (maybe False isToolTag) [runGHCVer, runCabalVer, runHLSVer, runStackVer]) || runInstTool'
+   r <- if not runQuick
         then runRUN runAppState $ do
          toolchain <- liftE resolveToolchainFull
-         tmp <- case runBinDir of
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
+         tmp <- liftIO $ createTmpDir toolchain
          liftE $ installToolChainFull toolchain tmp
          pure tmp
         else runLeanRUN leanAppstate $ do
          toolchain <- resolveToolchain
-         tmp <- case runBinDir of
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
+         tmp <- liftIO $ createTmpDir toolchain
          liftE $ installToolChain toolchain tmp
          pure tmp
    case r of
@@ -269,9 +258,16 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
 
   where
 
-   isToolTag :: ToolVersion -> Bool
-   isToolTag (ToolTag _) = True
-   isToolTag _           = False
+   createTmpDir :: Toolchain -> IO FilePath
+   createTmpDir toolchain =
+     case runBinDir of
+           Just bindir -> do
+             createDirRecursive' bindir
+             canonicalizePath bindir
+           Nothing -> do
+             d <- predictableTmpDir toolchain
+             createDirRecursive' d
+             canonicalizePath d
 
    -- TODO: doesn't work for cross
    resolveToolchainFull :: ( MonadFail m
@@ -351,25 +347,25 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
              Just (GHC, v) -> do
                unless isInstalled $ when (runInstTool' && isNothing (_tvTarget v)) $ void $ liftE $ installGHCBin
                  (_tvVersion v)
-                 Nothing
+                 GHCupInternal
                  False
                setTool GHC v tmp
              Just (Cabal, v) -> do
                unless isInstalled $ when runInstTool' $ void $ liftE $ installCabalBin
                  (_tvVersion v)
-                 Nothing
+                 GHCupInternal
                  False
                setTool Cabal v tmp
              Just (Stack, v) -> do
                unless isInstalled $ when runInstTool' $ void $ liftE $ installStackBin
                  (_tvVersion v)
-                 Nothing
+                 GHCupInternal
                  False
                setTool Stack v tmp
              Just (HLS, v) -> do
                unless isInstalled $ when runInstTool' $ void $ liftE $ installHLSBin
                  (_tvVersion v)
-                 Nothing
+                 GHCupInternal
                  False
                setTool HLS v tmp
              _ -> pure ()

docs/guide.md

@@ -228,6 +228,8 @@ See `ghcup compile ghc --help` for further information.
 
 ## Isolated installs
 
+**Before using isolated installs, make sure to have at least GHCup version 0.1.17.8!**
+
 Ghcup also enables you to install a tool (GHC, Cabal, HLS, Stack) at an isolated location of your choosing.
 These installs, as the name suggests, are separate from your main installs and DO NOT conflict with them.
 

docs/install.md

@@ -105,7 +105,8 @@ GHCup supports the following tools, which are also known as the **Haskell Toolch
 <table>
 <thead><tr><th>HLS Version</th><th>Tags</th></tr></thead>
 <tbody>
-<tr><td>1.6.1.0</td><td><span style="color:blue">latest</span>, <span style="color:green">recommended</span></td></tr>
+<tr><td>1.7.0.0</td><td><span style="color:blue">latest</span>, <span style="color:green">recommended</span></td></tr>
+<tr><td>1.6.1.0</td><td></td></tr>
 <tr><td>1.6.0.0</td><td></td></tr>
 <tr><td>1.5.1</td><td></td></tr>
 <tr><td>1.5.0</td><td></td></tr>

ghcup.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ghcup
-version:            0.1.17.7
+version:            0.1.17.8
 license:            LGPL-3.0-only
 license-file:       LICENSE
 copyright:          Julian Ospald 2020

lib/GHCup.hs

@@ -187,7 +187,7 @@ installGHCBindist :: ( MonadFail m
                      )
                   => DownloadInfo    -- ^ where/how to download
                   -> Version         -- ^ the version to install
-                  -> Maybe FilePath  -- ^ isolated filepath if user passed any
+                  -> InstallDir
                   -> Bool            -- ^ Force install
                   -> Excepts
                        '[ AlreadyInstalled
@@ -205,22 +205,22 @@ installGHCBindist :: ( MonadFail m
                         ]
                        m
                        ()
-installGHCBindist dlinfo ver isoFilepath forceInstall = do
+installGHCBindist dlinfo ver installDir forceInstall = do
   let tver = mkTVer ver
 
   lift $ logDebug $ "Requested to install GHC with " <> prettyVer ver
 
   regularGHCInstalled <- lift $ checkIfToolInstalled GHC ver
-  
+
   if
     | not forceInstall
     , regularGHCInstalled
-    , Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         throwE $ AlreadyInstalled GHC ver
 
     | forceInstall
     , regularGHCInstalled
-    , Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         lift $ logInfo "Removing the currently installed GHC version first!"
         liftE $ rmGHCVer tver
 
@@ -229,17 +229,18 @@ installGHCBindist dlinfo ver isoFilepath forceInstall = do
   -- download (or use cached version)
   dl <- liftE $ downloadCached dlinfo Nothing
 
-  -- prepare paths
-  ghcdir <- lift $ ghcupGHCDir tver
 
   toolchainSanityChecks
 
-  case isoFilepath of
-    Just isoDir -> do                        -- isolated install
+  case installDir of
+    IsolateDir isoDir -> do                        -- isolated install
       lift $ logInfo $ "isolated installing GHC to " <> T.pack isoDir
-      liftE $ installPackedGHC dl (view dlSubdir dlinfo) isoDir ver forceInstall
-    Nothing -> do                            -- regular install
-      liftE $ installPackedGHC dl (view dlSubdir dlinfo) ghcdir ver forceInstall
+      liftE $ installPackedGHC dl (view dlSubdir dlinfo) (IsolateDirResolved isoDir) ver forceInstall
+    GHCupInternal -> do                            -- regular install
+      -- prepare paths
+      ghcdir <- lift $ ghcupGHCDir tver
+
+      liftE $ installPackedGHC dl (view dlSubdir dlinfo) (GHCupDir ghcdir) ver forceInstall
 
       -- make symlinks & stuff when regular install,
       liftE $ postGHCInstall tver
@@ -271,7 +272,7 @@ installPackedGHC :: ( MonadMask m
                     )
                  => FilePath          -- ^ Path to the packed GHC bindist
                  -> Maybe TarDir      -- ^ Subdir of the archive
-                 -> FilePath          -- ^ Path to install to
+                 -> InstallDirResolved
                  -> Version           -- ^ The GHC version
                  -> Bool              -- ^ Force install
                  -> Excepts
@@ -297,9 +298,13 @@ installPackedGHC dl msubdir inst ver forceInstall = do
   workdir <- maybe (pure tmpUnpack)
                    (liftE . intoSubdir tmpUnpack)
                    msubdir
-  
+
   liftE $ runBuildAction tmpUnpack
-                         (Just inst)
+                         (case inst of
+                           IsolateDirResolved _ -> Nothing -- don't clean up for isolated installs, since that'd potentially delete other
+                                                   -- user files if '--force' is supplied
+                           GHCupDir d -> Just d
+                           )
                          (installUnpackedGHC workdir inst ver)
 
 
@@ -315,9 +320,9 @@ installUnpackedGHC :: ( MonadReader env m
                       , MonadUnliftIO m
                       , MonadMask m
                       )
-                   => FilePath      -- ^ Path to the unpacked GHC bindist (where the configure script resides)
-                   -> FilePath      -- ^ Path to install to
-                   -> Version       -- ^ The GHC version
+                   => FilePath            -- ^ Path to the unpacked GHC bindist (where the configure script resides)
+                   -> InstallDirResolved  -- ^ Path to install to
+                   -> Version             -- ^ The GHC version
                    -> Excepts '[ProcessError] m ()
 installUnpackedGHC path inst ver
   | isWindows = do
@@ -325,7 +330,10 @@ installUnpackedGHC path inst ver
       -- Windows bindists are relocatable and don't need
       -- to run configure.
       -- We also must make sure to preserve mtime to not confuse ghc-pkg.
-      lift $ withRunInIO $ \run -> flip onException (run $ recyclePathForcibly inst) $ copyDirectoryRecursive path inst $ \source dest -> do
+      lift $ withRunInIO $ \run -> flip onException (case inst of
+                                                      IsolateDirResolved _ -> pure ()
+                                                      GHCupDir d -> run $ recyclePathForcibly d
+                                                    ) $ copyDirectoryRecursive path (fromInstallDir inst) $ \source dest -> do
         mtime <- getModificationTime source
         moveFilePortable source dest
         setModificationTime dest mtime
@@ -340,7 +348,7 @@ installUnpackedGHC path inst ver
 
       lift $ logInfo "Installing GHC (this may take a while)"
       lEM $ execLogged "sh"
-                       ("./configure" : ("--prefix=" <> inst) 
+                       ("./configure" : ("--prefix=" <> fromInstallDir inst)
                         : alpineArgs
                        )
                        (Just path)
@@ -369,7 +377,7 @@ installGHCBin :: ( MonadFail m
                  , MonadUnliftIO m
                  )
               => Version         -- ^ the version to install
-              -> Maybe FilePath  -- ^ isolated install filepath, if user passed any
+              -> InstallDir
               -> Bool            -- ^ force install
               -> Excepts
                    '[ AlreadyInstalled
@@ -387,9 +395,9 @@ installGHCBin :: ( MonadFail m
                     ]
                    m
                    ()
-installGHCBin ver isoFilepath forceInstall = do
+installGHCBin ver installDir forceInstall = do
   dlinfo <- liftE $ getDownloadInfo GHC ver
-  liftE $ installGHCBindist dlinfo ver isoFilepath forceInstall
+  liftE $ installGHCBindist dlinfo ver installDir forceInstall
 
 
 -- | Like 'installCabalBin', except takes the 'DownloadInfo' as
@@ -408,8 +416,8 @@ installCabalBindist :: ( MonadMask m
                        )
                     => DownloadInfo
                     -> Version
-                    -> Maybe FilePath -- ^ isolated install filepath, if user provides any.
-                    -> Bool           -- ^ Force install 
+                    -> InstallDir
+                    -> Bool           -- ^ Force install
                     -> Excepts
                          '[ AlreadyInstalled
                           , CopyError
@@ -425,7 +433,7 @@ installCabalBindist :: ( MonadMask m
                           ]
                          m
                          ()
-installCabalBindist dlinfo ver isoFilepath forceInstall = do
+installCabalBindist dlinfo ver installDir forceInstall = do
   lift $ logDebug $ "Requested to install cabal version " <> prettyVer ver
 
   PlatformRequest {..} <- lift getPlatformReq
@@ -437,18 +445,18 @@ installCabalBindist dlinfo ver isoFilepath forceInstall = do
   if
     | not forceInstall
     , regularCabalInstalled
-    ,  Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         throwE $ AlreadyInstalled Cabal ver
-        
+
     | forceInstall
     , regularCabalInstalled
-    , Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         lift $ logInfo "Removing the currently installed version first!"
         liftE $ rmCabalVer ver
 
     | otherwise -> pure ()
 
-               
+
   -- download (or use cached version)
   dl <- liftE $ downloadCached dlinfo Nothing
 
@@ -460,34 +468,37 @@ installCabalBindist dlinfo ver isoFilepath forceInstall = do
   -- the subdir of the archive where we do the work
   workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
 
-  case isoFilepath of
-    Just isoDir -> do             -- isolated install
+  case installDir of
+    IsolateDir isoDir -> do             -- isolated install
       lift $ logInfo $ "isolated installing Cabal to " <> T.pack isoDir
-      liftE $ installCabalUnpacked workdir isoDir Nothing forceInstall
+      liftE $ installCabalUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
+
+    GHCupInternal -> do                 -- regular install
+      liftE $ installCabalUnpacked workdir (GHCupDir binDir) ver forceInstall
 
-    Nothing -> do                 -- regular install
-      liftE $ installCabalUnpacked workdir binDir (Just ver) forceInstall
 
-      
 -- | Install an unpacked cabal distribution.Symbol
 installCabalUnpacked :: (MonadCatch m, HasLog env, MonadIO m, MonadReader env m)
               => FilePath      -- ^ Path to the unpacked cabal bindist (where the executable resides)
-              -> FilePath      -- ^ Path to install to
-              -> Maybe Version -- ^ Nothing for isolated install
+              -> InstallDirResolved      -- ^ Path to install to
+              -> Version
               -> Bool          -- ^ Force Install
               -> Excepts '[CopyError, FileAlreadyExistsError] m ()
-installCabalUnpacked path inst mver' forceInstall = do
+installCabalUnpacked path inst ver forceInstall = do
   lift $ logInfo "Installing cabal"
   let cabalFile = "cabal"
-  liftIO $ createDirRecursive' inst
+  liftIO $ createDirRecursive' (fromInstallDir inst)
   let destFileName = cabalFile
-        <> maybe "" (("-" <>) . T.unpack . prettyVer) mver'
+        <> (case inst of
+              IsolateDirResolved _ -> ""
+              GHCupDir _ -> ("-" <>) . T.unpack . prettyVer $ ver
+           )
         <> exeExt
-  let destPath = inst </> destFileName
+  let destPath = fromInstallDir inst </> destFileName
 
   unless forceInstall          -- Overwrite it when it IS a force install
     (liftE $ throwIfFileAlreadyExists destPath)
-    
+
   copyFileE
     (path </> cabalFile <> exeExt)
     destPath
@@ -510,7 +521,7 @@ installCabalBin :: ( MonadMask m
                    , MonadFail m
                    )
                 => Version
-                -> Maybe FilePath -- isolated install Path, if user provided any
+                -> InstallDir
                 -> Bool           -- force install
                 -> Excepts
                      '[ AlreadyInstalled
@@ -527,9 +538,9 @@ installCabalBin :: ( MonadMask m
                       ]
                      m
                      ()
-installCabalBin ver isoFilepath forceInstall = do
+installCabalBin ver installDir forceInstall = do
   dlinfo <- liftE $ getDownloadInfo Cabal ver
-  installCabalBindist dlinfo ver isoFilepath forceInstall
+  installCabalBindist dlinfo ver installDir forceInstall
 
 
 -- | Like 'installHLSBin, except takes the 'DownloadInfo' as
@@ -548,8 +559,8 @@ installHLSBindist :: ( MonadMask m
                      )
                   => DownloadInfo
                   -> Version
-                  -> Maybe FilePath -- ^ isolated install path, if user passed any
-                  -> Bool           -- ^ Force install
+                  -> InstallDir -- ^ isolated install path, if user passed any
+                  -> Bool       -- ^ Force install
                   -> Excepts
                        '[ AlreadyInstalled
                         , CopyError
@@ -567,7 +578,7 @@ installHLSBindist :: ( MonadMask m
                         ]
                        m
                        ()
-installHLSBindist dlinfo ver isoFilepath forceInstall = do
+installHLSBindist dlinfo ver installDir forceInstall = do
   lift $ logDebug $ "Requested to install hls version " <> prettyVer ver
 
   PlatformRequest {..} <- lift getPlatformReq
@@ -578,17 +589,17 @@ installHLSBindist dlinfo ver isoFilepath forceInstall = do
   if
     | not forceInstall
     , regularHLSInstalled
-    , Nothing <- isoFilepath -> do      -- regular install
+    , GHCupInternal <- installDir -> do        -- regular install
         throwE $ AlreadyInstalled HLS ver
 
     | forceInstall
     , regularHLSInstalled
-    , Nothing <- isoFilepath -> do      -- regular forced install
+    , GHCupInternal <- installDir -> do        -- regular forced install
         lift $ logInfo "Removing the currently installed version of HLS before force installing!"
         liftE $ rmHLSVer ver
 
     | otherwise -> pure ()
-    
+
   -- download (or use cached version)
   dl <- liftE $ downloadCached dlinfo Nothing
 
@@ -604,22 +615,23 @@ installHLSBindist dlinfo ver isoFilepath forceInstall = do
   if
     | not forceInstall
     , not legacy
-    , (Just fp) <- isoFilepath -> liftE $ installDestSanityCheck fp
+    , (IsolateDir fp) <- installDir -> liftE $ installDestSanityCheck (IsolateDirResolved fp)
     | otherwise -> pure ()
 
-  case isoFilepath of
-    Just isoDir -> do
+  case installDir of
+    IsolateDir isoDir -> do
       lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
       if legacy
-      then liftE $ installHLSUnpackedLegacy workdir isoDir Nothing forceInstall
-      else liftE $ runBuildAction tmpUnpack Nothing $ installHLSUnpacked workdir isoDir ver
+      then liftE $ installHLSUnpackedLegacy workdir (IsolateDirResolved isoDir) ver forceInstall
+      else liftE $ runBuildAction tmpUnpack Nothing $ installHLSUnpacked workdir (IsolateDirResolved isoDir) ver
 
-    Nothing -> do
+    GHCupInternal -> do
       if legacy
-      then liftE $ installHLSUnpackedLegacy workdir binDir (Just ver) forceInstall
+      then liftE $ installHLSUnpackedLegacy workdir (GHCupDir binDir) ver forceInstall
       else do
         inst <- ghcupHLSDir ver
-        liftE $ runBuildAction tmpUnpack Nothing $ installHLSUnpacked workdir inst ver
+        liftE $ runBuildAction tmpUnpack (Just inst)
+              $ installHLSUnpacked workdir (GHCupDir inst) ver
         liftE $ setHLS ver SetHLS_XYZ Nothing
 
 
@@ -631,10 +643,10 @@ isLegacyHLSBindist path = do
 -- | Install an unpacked hls distribution.
 installHLSUnpacked :: (MonadMask m, MonadUnliftIO m, MonadReader env m, MonadFail m, HasLog env, HasDirs env, HasSettings env, MonadCatch m, MonadIO m)
                    => FilePath      -- ^ Path to the unpacked hls bindist (where the executable resides)
-                   -> FilePath      -- ^ Path to install to
+                   -> InstallDirResolved      -- ^ Path to install to
                    -> Version
                    -> Excepts '[ProcessError, CopyError, FileAlreadyExistsError, NotInstalled] m ()
-installHLSUnpacked path inst _ = do
+installHLSUnpacked path (fromInstallDir -> inst) _ = do
   lift $ logInfo "Installing HLS"
   liftIO $ createDirRecursive' inst
   lEM $ make ["PREFIX=" <> inst, "install"] (Just path)
@@ -642,13 +654,13 @@ installHLSUnpacked path inst _ = do
 -- | Install an unpacked hls distribution (legacy).
 installHLSUnpackedLegacy :: (MonadReader env m, MonadFail m, HasLog env, MonadCatch m, MonadIO m)
                          => FilePath      -- ^ Path to the unpacked hls bindist (where the executable resides)
-                         -> FilePath      -- ^ Path to install to
-                         -> Maybe Version -- ^ Nothing for isolated install
+                         -> InstallDirResolved      -- ^ Path to install to
+                         -> Version
                          -> Bool          -- ^ is it a force install
                          -> Excepts '[CopyError, FileAlreadyExistsError] m ()
-installHLSUnpackedLegacy path inst mver' forceInstall = do
+installHLSUnpackedLegacy path installDir ver forceInstall = do
   lift $ logInfo "Installing HLS"
-  liftIO $ createDirRecursive' inst
+  liftIO $ createDirRecursive' (fromInstallDir installDir)
 
   -- install haskell-language-server-<ghcver>
   bins@(_:_) <- liftIO $ findFiles
@@ -659,15 +671,18 @@ installHLSUnpackedLegacy path inst mver' forceInstall = do
     )
   forM_ bins $ \f -> do
     let toF = dropSuffix exeExt f
-              <> maybe "" (("~" <>) . T.unpack . prettyVer) mver'
+              <> (case installDir of
+                   IsolateDirResolved _ -> ""
+                   GHCupDir _ -> ("~" <>) . T.unpack . prettyVer $ ver
+                 )
               <> exeExt
 
     let srcPath = path </> f
-    let destPath = inst </> toF
+    let destPath = fromInstallDir installDir </> toF
 
     unless forceInstall   -- if it is a force install, overwrite it.
       (liftE $ throwIfFileAlreadyExists destPath)
-      
+
     copyFileE
       srcPath
       destPath
@@ -676,18 +691,21 @@ installHLSUnpackedLegacy path inst mver' forceInstall = do
   -- install haskell-language-server-wrapper
   let wrapper = "haskell-language-server-wrapper"
       toF = wrapper
-            <> maybe "" (("-" <>) . T.unpack . prettyVer) mver'
+            <> (case installDir of
+                 IsolateDirResolved _ -> ""
+                 GHCupDir _ -> ("-" <>) . T.unpack . prettyVer $ ver
+               )
             <> exeExt
       srcWrapperPath = path </> wrapper <> exeExt
-      destWrapperPath = inst </> toF
+      destWrapperPath = fromInstallDir installDir </> toF
 
   unless forceInstall
     (liftE $ throwIfFileAlreadyExists destWrapperPath)
-      
+
   copyFileE
     srcWrapperPath
     destWrapperPath
-    
+
   lift $ chmod_755 destWrapperPath
 
 
@@ -708,7 +726,7 @@ installHLSBin :: ( MonadMask m
                  , MonadFail m
                  )
               => Version
-              -> Maybe FilePath  -- isolated install Dir (if any)
+              -> InstallDir
               -> Bool            -- force install
               -> Excepts
                    '[ AlreadyInstalled
@@ -727,9 +745,9 @@ installHLSBin :: ( MonadMask m
                     ]
                    m
                    ()
-installHLSBin ver isoFilepath forceInstall = do
+installHLSBin ver installDir forceInstall = do
   dlinfo <- liftE $ getDownloadInfo HLS ver
-  installHLSBindist dlinfo ver isoFilepath forceInstall
+  installHLSBindist dlinfo ver installDir forceInstall
 
 
 compileHLS :: ( MonadMask m
@@ -749,7 +767,7 @@ compileHLS :: ( MonadMask m
            -> [Version]
            -> Maybe Int
            -> Maybe Version
-           -> Maybe FilePath
+           -> InstallDir
            -> Maybe (Either FilePath URI)
            -> Maybe URI
            -> Maybe (Either FilePath [URI])  -- ^ patches
@@ -764,7 +782,7 @@ compileHLS :: ( MonadMask m
                        , BuildFailed
                        , NotInstalled
                        ] m Version
-compileHLS targetHLS ghcs jobs ov isolateDir cabalProject cabalProjectLocal patches cabalArgs = do
+compileHLS targetHLS ghcs jobs ov installDir cabalProject cabalProjectLocal patches cabalArgs = do
   PlatformRequest { .. } <- lift getPlatformReq
   GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
   Dirs { .. } <- lift getDirs
@@ -805,7 +823,7 @@ compileHLS targetHLS ghcs jobs ov isolateDir cabalProject cabalProjectLocal patc
                   , "origin"
                   , fromString rep ]
 
-        let fetch_args = 
+        let fetch_args =
                   [ "fetch"
                   , "--depth"
                   , "1"
@@ -837,8 +855,8 @@ compileHLS targetHLS ghcs jobs ov isolateDir cabalProject cabalProjectLocal patc
     workdir
     Nothing
     (reThrowAll @_ @'[GPGError, DownloadFailed, DigestError, PatchFailed, ProcessError, FileAlreadyExistsError, CopyError] @'[BuildFailed] (BuildFailed workdir) $ do
-      let installDir = workdir </> "out"
-      liftIO $ createDirRecursive' installDir
+      let tmpInstallDir = workdir </> "out"
+      liftIO $ createDirRecursive' tmpInstallDir
 
       -- apply patches
       liftE $ applyAnyPatch patches workdir
@@ -861,8 +879,8 @@ compileHLS targetHLS ghcs jobs ov isolateDir cabalProject cabalProjectLocal patc
         cpl <- liftE $ download uri Nothing Nothing tmpUnpack (Just (cp <.> "local")) False
         copyFileE cpl (workdir </> cp <.> "local")
       artifacts <- forM (sort ghcs) $ \ghc -> do
-        let ghcInstallDir = installDir </> T.unpack (prettyVer ghc)
-        liftIO $ createDirRecursive' installDir
+        let ghcInstallDir = tmpInstallDir </> T.unpack (prettyVer ghc)
+        liftIO $ createDirRecursive' tmpInstallDir
         lift $ logInfo $ "Building HLS " <> prettyVer installVer <> " for GHC version " <> prettyVer ghc
         liftE $ lEM @_ @'[ProcessError] $
           execLogged "cabal" ( [ "v2-install"
@@ -885,17 +903,17 @@ compileHLS targetHLS ghcs jobs ov isolateDir cabalProject cabalProjectLocal patc
 
       forM_ artifacts $ \artifact -> do
         liftIO $ renameFile (artifact </> "haskell-language-server" <.> exeExt)
-          (installDir </> "haskell-language-server-" <> takeFileName artifact <.> exeExt)
+          (tmpInstallDir </> "haskell-language-server-" <> takeFileName artifact <.> exeExt)
         liftIO $ renameFile (artifact </> "haskell-language-server-wrapper" <.> exeExt)
-          (installDir </> "haskell-language-server-wrapper" <.> exeExt)
+          (tmpInstallDir </> "haskell-language-server-wrapper" <.> exeExt)
         liftIO $ rmPathForcibly artifact
 
-      case isolateDir of
-        Just isoDir -> do
+      case installDir of
+        IsolateDir isoDir -> do
           lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
-          liftE $ installHLSUnpackedLegacy installDir isoDir Nothing True
-        Nothing -> do
-          liftE $ installHLSUnpackedLegacy installDir binDir (Just installVer) True
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (IsolateDirResolved isoDir) installVer True
+        GHCupInternal -> do
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (GHCupDir binDir) installVer True
     )
 
   pure installVer
@@ -919,7 +937,7 @@ installStackBin :: ( MonadMask m
                    , MonadFail m
                    )
                 => Version
-                -> Maybe FilePath  -- ^ isolate install Dir (if any)
+                -> InstallDir
                 -> Bool            -- ^ Force install
                 -> Excepts
                      '[ AlreadyInstalled
@@ -936,9 +954,9 @@ installStackBin :: ( MonadMask m
                       ]
                      m
                      ()
-installStackBin ver isoFilepath forceInstall = do
+installStackBin ver installDir forceInstall = do
   dlinfo <- liftE $ getDownloadInfo Stack ver
-  installStackBindist dlinfo ver isoFilepath forceInstall
+  installStackBindist dlinfo ver installDir forceInstall
 
 
 -- | Like 'installStackBin', except takes the 'DownloadInfo' as
@@ -957,7 +975,7 @@ installStackBindist :: ( MonadMask m
                        )
                     => DownloadInfo
                     -> Version
-                    -> Maybe FilePath -- ^ isolate install Dir (if any)
+                    -> InstallDir
                     -> Bool           -- ^ Force install
                     -> Excepts
                          '[ AlreadyInstalled
@@ -974,7 +992,7 @@ installStackBindist :: ( MonadMask m
                           ]
                          m
                          ()
-installStackBindist dlinfo ver isoFilepath forceInstall = do
+installStackBindist dlinfo ver installDir forceInstall = do
   lift $ logDebug $ "Requested to install stack version " <> prettyVer ver
 
   PlatformRequest {..} <- lift getPlatformReq
@@ -985,12 +1003,12 @@ installStackBindist dlinfo ver isoFilepath forceInstall = do
   if
     | not forceInstall
     , regularStackInstalled
-    , Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         throwE $ AlreadyInstalled Stack ver
 
     | forceInstall
     , regularStackInstalled
-    , Nothing <- isoFilepath -> do
+    , GHCupInternal <- installDir -> do
         lift $ logInfo "Removing the currently installed version of Stack first!"
         liftE $ rmStackVer ver
 
@@ -1007,33 +1025,36 @@ installStackBindist dlinfo ver isoFilepath forceInstall = do
   -- the subdir of the archive where we do the work
   workdir <- maybe (pure tmpUnpack) (liftE . intoSubdir tmpUnpack) (view dlSubdir dlinfo)
 
-  case isoFilepath of
-    Just isoDir -> do                 -- isolated install
+  case installDir of
+    IsolateDir isoDir -> do                 -- isolated install
       lift $ logInfo $ "isolated installing Stack to " <> T.pack isoDir
-      liftE $ installStackUnpacked workdir isoDir Nothing forceInstall
-    Nothing -> do                     -- regular install
-      liftE $ installStackUnpacked workdir binDir (Just ver) forceInstall
+      liftE $ installStackUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
+    GHCupInternal -> do                     -- regular install
+      liftE $ installStackUnpacked workdir (GHCupDir binDir) ver forceInstall
 
 
 -- | Install an unpacked stack distribution.
 installStackUnpacked :: (MonadReader env m, HasLog env, MonadCatch m, MonadIO m)
               => FilePath      -- ^ Path to the unpacked stack bindist (where the executable resides)
-              -> FilePath      -- ^ Path to install to
-              -> Maybe Version -- ^ Nothing for isolated installs
+              -> InstallDirResolved
+              -> Version
               -> Bool          -- ^ Force install
               -> Excepts '[CopyError, FileAlreadyExistsError] m ()
-installStackUnpacked path inst mver' forceInstall = do
+installStackUnpacked path installDir ver forceInstall = do
   lift $ logInfo "Installing stack"
   let stackFile = "stack"
-  liftIO $ createDirRecursive' inst
+  liftIO $ createDirRecursive' (fromInstallDir installDir)
   let destFileName = stackFile
-                     <> maybe "" (("-" <>) .  T.unpack . prettyVer) mver'
+                     <> (case installDir of
+                          IsolateDirResolved _ -> ""
+                          GHCupDir _ -> ("-" <>) .  T.unpack . prettyVer $ ver
+                        )
                      <> exeExt
-      destPath = inst </> destFileName
+      destPath = fromInstallDir installDir </> destFileName
 
   unless forceInstall
     (liftE $ throwIfFileAlreadyExists destPath)
-      
+
   copyFileE
     (path </> stackFile <> exeExt)
     destPath
@@ -1099,7 +1120,7 @@ setGHC ver sghc mBinDir = do
       SetGHC_XY  -> do
         handle
             (\(e :: ParseError) -> lift $ logWarn (T.pack $ displayException e) >> pure Nothing)
-          $ do 
+          $ do
             (mj, mi) <- getMajorMinorV (_tvVersion ver)
             let major' = intToText mj <> "." <> intToText mi
             pure $ Just (file <> "-" <> T.unpack major')
@@ -1223,7 +1244,7 @@ setHLS :: ( MonadReader env m
           , MonadUnliftIO m
           )
        => Version
-       -> SetHLS -- Nothing for legacy
+       -> SetHLS
        -> Maybe FilePath  -- if set, signals that we're not operating in ~/.ghcup/bin
                           -- and don't want mess with other versions
        -> Excepts '[NotInstalled] m ()
@@ -1357,7 +1378,7 @@ warnAboutHlsCompatibility = do
         "Haskell IDE support may not work until this is fixed." <> "\n" <>
         "Install a different HLS version, or install and set one of the following GHCs:" <> "\n" <>
         T.pack (prettyShow supportedGHC)
-        
+
     _ -> return ()
 
     ------------------
@@ -1962,7 +1983,7 @@ rmGhcupDirs = do
 
   handleRm $ rmEnvFile  envFilePath
   handleRm $ rmConfFile confFilePath
-  
+
   -- for xdg dirs, the order matters here
   handleRm $ rmDir logsDir
   handleRm $ rmDir cacheDir
@@ -2036,7 +2057,7 @@ rmGhcupDirs = do
       cs <- liftIO $ listDirectory fp >>= filterM doesDirectoryExist . fmap (fp </>)
       forM_ cs removeEmptyDirsRecursive
       hideError InappropriateType $ removeDirIfEmptyOrIsSymlink fp
-        
+
 
     -- we expect only files inside cache/log dir
     -- we report remaining files/dirs later,
@@ -2121,7 +2142,7 @@ compileGHC :: ( MonadMask m
            -> [Text]                   -- ^ additional args to ./configure
            -> Maybe String             -- ^ build flavour
            -> Bool
-           -> Maybe FilePath           -- ^ isolate dir
+           -> InstallDir
            -> Excepts
                 '[ AlreadyInstalled
                  , BuildFailed
@@ -2146,7 +2167,7 @@ compileGHC :: ( MonadMask m
                  ]
                 m
                 GHCTargetVersion
-compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadrian isolateDir
+compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadrian installDir
   = do
     PlatformRequest { .. } <- lift getPlatformReq
     GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
@@ -2187,7 +2208,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                     , "origin"
                     , fromString rep ]
 
-          let fetch_args = 
+          let fetch_args =
                     [ "fetch"
                     , "--depth"
                     , "1"
@@ -2219,18 +2240,18 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
     alreadySet <- fmap (== Just installVer) $ lift $ ghcSet (_tvTarget installVer)
 
     when alreadyInstalled $ do
-      case isolateDir of
-        Just isoDir ->
+      case installDir of
+        IsolateDir isoDir ->
           lift $ logWarn $ "GHC " <> T.pack (prettyShow installVer) <> " already installed. Isolate installing to " <> T.pack isoDir
-        Nothing ->
+        GHCupInternal ->
           lift $ logWarn $ "GHC " <> T.pack (prettyShow installVer) <> " already installed. Will overwrite existing version."
       lift $ logWarn
         "...waiting for 10 seconds before continuing, you can still abort..."
       liftIO $ threadDelay 10000000 -- give the user a sec to intervene
 
-    ghcdir <- case isolateDir of
-      Just isoDir -> pure isoDir
-      Nothing -> lift $ ghcupGHCDir installVer
+    ghcdir <- case installDir of
+      IsolateDir isoDir -> pure $ IsolateDirResolved isoDir
+      GHCupInternal -> GHCupDir <$> lift (ghcupGHCDir installVer)
 
     (mBindist, bmk) <- liftE $ runBuildAction
       tmpUnpack
@@ -2243,13 +2264,13 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
         pure (b, bmk)
       )
 
-    case isolateDir of
-      Nothing ->
+    case installDir of
+      GHCupInternal ->
         -- only remove old ghc in regular installs
         when alreadyInstalled $ do
           lift $ logInfo "Deleting existing installation"
           liftE $ rmGHCVer installVer
-          
+
       _ -> pure ()
 
     forM_ mBindist $ \bindist -> do
@@ -2259,21 +2280,21 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                                (installVer ^. tvVersion)
                                False       -- not a force install, since we already overwrite when compiling.
 
-    liftIO $ B.writeFile (ghcdir </> ghcUpSrcBuiltFile) bmk
-    
-    case isolateDir of
+    liftIO $ B.writeFile (fromInstallDir ghcdir </> ghcUpSrcBuiltFile) bmk
+
+    case installDir of
       -- set and make symlinks for regular (non-isolated) installs
-      Nothing -> do
+      GHCupInternal -> do
         reThrowAll GHCupSetError $ postGHCInstall installVer
         -- restore
         when alreadySet $ liftE $ void $ setGHC installVer SetGHCOnly Nothing
-        
+
       _ -> pure ()
 
     pure installVer
 
  where
-  defaultConf = 
+  defaultConf =
     let cross_mk = $(LitE . StringL <$> (qAddDependentFile "data/build_mk/cross" >> runIO (readFile "data/build_mk/cross")))
         default_mk = $(LitE . StringL <$> (qAddDependentFile "data/build_mk/default" >> runIO (readFile "data/build_mk/default")))
     in case targetGhc of
@@ -2292,7 +2313,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                            )
                         => GHCTargetVersion
                         -> FilePath
-                        -> FilePath
+                        -> InstallDirResolved
                         -> Excepts
                              '[ FileDoesNotExistError
                               , HadrianNotFound
@@ -2351,7 +2372,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                         )
                      => GHCTargetVersion
                      -> FilePath
-                     -> FilePath
+                     -> InstallDirResolved
                      -> Excepts
                           '[ FileDoesNotExistError
                            , HadrianNotFound
@@ -2486,7 +2507,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                       )
                    => GHCTargetVersion
                    -> FilePath
-                   -> FilePath
+                   -> InstallDirResolved
                    -> Excepts
                         '[ FileDoesNotExistError
                          , InvalidBuildConfig
@@ -2497,7 +2518,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                          ]
                         m
                         ()
-  configureBindist tver workdir ghcdir = do
+  configureBindist tver workdir (fromInstallDir -> ghcdir) = do
     lift $ logInfo [s|configuring build|]
 
     if | _tvVersion tver >= [vver|8.8.0|] -> do

lib/GHCup/Types.hs

@@ -628,3 +628,16 @@ data CapturedProcess = CapturedProcess
   deriving (Eq, Show)
 
 makeLenses ''CapturedProcess
+
+
+data InstallDir = IsolateDir FilePath
+                | GHCupInternal
+  deriving (Eq, Show)
+
+data InstallDirResolved = IsolateDirResolved FilePath
+                        | GHCupDir FilePath
+  deriving (Eq, Show)
+
+fromInstallDir :: InstallDirResolved -> FilePath
+fromInstallDir (IsolateDirResolved fp) = fp
+fromInstallDir (GHCupDir fp) = fp

lib/GHCup/Utils.hs

@@ -1265,9 +1265,10 @@ ghcBinaryName (GHCTargetVersion Nothing  _) = T.unpack ("ghc" <> T.pack exeExt)
 installDestSanityCheck :: ( MonadIO m
                           , MonadCatch m
                           ) =>
-                          FilePath ->
+                          InstallDirResolved ->
                           Excepts '[DirNotEmpty] m ()
-installDestSanityCheck isoDir = do
+installDestSanityCheck (IsolateDirResolved isoDir) = do
   hideErrorDef [doesNotExistErrorType] () $ do
     contents <- liftIO $ getDirectoryContentsRecursive isoDir
     unless (null contents) (throwE $ DirNotEmpty isoDir)
+installDestSanityCheck _ = pure ()

scripts/bootstrap/bootstrap-haskell

@@ -26,7 +26,7 @@
 
 plat="$(uname -s)"
 arch=$(uname -m)
-ghver="0.1.17.7"
+ghver="0.1.17.8"
 : "${GHCUP_BASE_URL:=https://downloads.haskell.org/~ghcup}"
 
 export GHCUP_SKIP_UPDATE_CHECK=yes

scripts/bootstrap/bootstrap-haskell.ps1

@@ -239,7 +239,27 @@ if ($Silent -and !($InstallDir)) {
   }
 } else {
   while ($true) {
-    Print-Msg -color Magenta -msg ('Where to install to (this should be a short Path, preferably a Drive like ''C:\''){1}Press enter to accept the default [{0}]:' -f $defaultGhcupBasePrefix, "`n")
+	Print-Msg -color Magenta -msg (@'
+Welcome to Haskell!
+
+This script will download and install the following programs:
+  * ghcup - The Haskell toolchain installer
+  * ghc   - The Glasgow Haskell Compiler
+  * msys2 - A linux-style toolchain environment required for many operations
+  * cabal - The Cabal build tool for managing Haskell software
+  * stack - (optional) A cross-platform program for developing Haskell projects
+  * hls   - (optional) A language server for developers to integrate with their editor/IDE
+
+Please note that ANTIVIRUS may interfere with the installation. If you experience problems, consider
+disabling it temporarily.
+
+Where to install to (this should be a short Path, preferably a Drive like 'C:\')?
+If you accept this path, binaries will be installed into '{0}ghcup\bin' and msys2 into '{0}ghcup\msys64'.
+Press enter to accept the default [{0}]:
+
+'@ -f $defaultGhcupBasePrefix)
+
+
     $basePrefixPrompt = Read-Host
     $GhcupBasePrefix = ($defaultGhcupBasePrefix,$basePrefixPrompt)[[bool]$basePrefixPrompt]
     if (!($GhcupBasePrefix.EndsWith('\'))) {

stack.yaml

@@ -1,4 +1,4 @@
-resolver: lts-18.27
+resolver: lts-18.28
 
 packages:
   - .