Merge branch 'issue-360'

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

.gitlab/script/ghcup_version.sh

@@ -176,6 +176,8 @@ else
 	[ "$(ghc --numeric-version)" = "${ghc_ver}" ]
 
 
+	ls -lah "$GHCUP_BIN"
+
 	if [ "${OS}" = "DARWIN" ] ; then
 		eghcup install hls
 		$(eghcup whereis hls) --version

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Revision history for ghcup
 
+## 0.1.17.8 -- XXXX-XX-XX
+
+* Fix HLS build not cleaning up properly on failed installations, fixes [#361](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/361)
+    - this also fixes a significant bug on installation failure when combining `--isolate DIR` with `--force`
+* 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 [#250](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/250)
+
+## 0.1.17.7 -- 2022-04-21
+
+* Fix `ghcup run` on windows wrt [#345](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/345)
+
 ## 0.1.17.6 -- 2022-03-18
 
 * Vastly improve shell completions wrt [#242](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/242)

app/ghcup/BrickMain.hs

@@ -437,6 +437,7 @@ install' _ (_, ListResult {..}) = do
               , TarDirDoesNotExist
               , FileAlreadyExistsError
               , ProcessError
+              , GHCupShadowed
               ]
 
   run (do
@@ -446,19 +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 $> (vi, dirs, ce)
+          liftE $ upgradeGHCup Nothing False False $> (vi, dirs, ce)
         HLS   -> do
           let vi = getVersionInfo lVer HLS dls
-          liftE $ installHLSBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installHLSBin lVer GHCupInternal False $> (vi, dirs, ce)
         Stack -> do
           let vi = getVersionInfo lVer Stack dls
-          liftE $ installStackBin lVer Nothing False $> (vi, dirs, ce)
+          liftE $ installStackBin lVer GHCupInternal False $> (vi, dirs, ce)
     )
     >>= \case
           VRight (vi, Dirs{..}, Just ce) -> do

app/ghcup/GHCup/OptParse.hs

@@ -96,7 +96,7 @@ data Command
   | Config ConfigCommand
   | Whereis WhereisOptions WhereisCommand
 #ifndef DISABLE_UPGRADE
-  | Upgrade UpgradeOpts Bool
+  | Upgrade UpgradeOpts Bool Bool
 #endif
   | ToolRequirements ToolReqOpts
   | ChangeLog ChangeLogOptions
@@ -222,18 +222,18 @@ com =
            (info (List <$> listOpts <**> helper)
                  (progDesc "Show available GHCs and other tools")
            )
-#ifndef DISABLE_UPGRADE
       <> command
            "upgrade"
            (info
              (    (Upgrade <$> upgradeOptsP <*> switch
                     (short 'f' <> long "force" <> help "Force update")
+                    <*> switch
+                    (long "fail-if-shadowed" <> help "Fails after upgrading if the upgraded ghcup binary is shadowed by something else in PATH (useful for CI)")
                   )
              <**> helper
              )
              (progDesc "Upgrade ghcup")
            )
-#endif
       <> command
            "compile"
            (   Compile

app/ghcup/GHCup/OptParse/Compile.hs

@@ -283,7 +283,7 @@ hlsCompileOpts =
           (short 'g' <> long "git-ref" <> metavar "GIT_REFERENCE" <> help
             "The git commit/branch/ref to build from"
           ) <*>
-          optional (option str (short 'r' <> long "repository" <> metavar "GIT_REPOSITORY" <> help "The git repository to build from (defaults to GHC upstream)"
+          optional (option str (short 'r' <> long "repository" <> metavar "GIT_REPOSITORY" <> help "The git repository to build from (defaults to HLS upstream)"
             <> completer (gitFileUri ["https://github.com/haskell/haskell-language-server.git"])
           ))
           )))
@@ -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 $

app/ghcup/GHCup/OptParse/Install.hs

@@ -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
@@ -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]
   }
 
@@ -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
+         tmp <- liftIO $ createTmpDir toolchain
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
          liftE $ installToolChainFull toolchain tmp
          pure tmp
         else runLeanRUN leanAppstate $ do
          toolchain <- resolveToolchain
-         tmp <- case runBinDir of
+         tmp <- liftIO $ createTmpDir toolchain
-           Just bindir -> do
-             liftIO $ createDirRecursive' bindir
-             liftIO $ canonicalizePath bindir
-           Nothing -> do
-             d <- liftIO $ predictableTmpDir toolchain
-             liftIO $ createDirRecursive' d
-             liftIO $ canonicalizePath d
          liftE $ installToolChain toolchain tmp
          pure tmp
    case r of
@@ -269,9 +258,16 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
 
   where
 
-   isToolTag :: ToolVersion -> Bool
+   createTmpDir :: Toolchain -> IO FilePath
-   isToolTag (ToolTag _) = True
+   createTmpDir toolchain =
-   isToolTag _           = False
+     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 ()

app/ghcup/GHCup/OptParse/Upgrade.hs

@@ -65,9 +65,10 @@ upgradeOptsP =
   flag'
       UpgradeInplace
       (short 'i' <> long "inplace" <> help
-        "Upgrade ghcup in-place (wherever it's at)"
+        "Upgrade ghcup in-place"
       )
-    <|> (   UpgradeAt
+    <|>
+      (   UpgradeAt
         <$> option
               str
               (short 't' <> long "target" <> metavar "TARGET_DIR" <> help
@@ -92,6 +93,7 @@ type UpgradeEffects = '[ DigestError
                        , FileDoesNotExistError
                        , CopyError
                        , DownloadFailed
+                       , GHCupShadowed
                        ]
 
 
@@ -120,18 +122,19 @@ upgrade :: ( Monad m
            )
         => UpgradeOpts
         -> Bool
+        -> Bool
         -> Dirs
         -> (forall a. ReaderT AppState m (VEither UpgradeEffects a) -> m (VEither UpgradeEffects a))
         -> (ReaderT LeanAppState m () -> m ())
         -> m ExitCode
-upgrade uOpts force' Dirs{..} runAppState runLogger = do
+upgrade uOpts force' fatal Dirs{..} runAppState runLogger = do
   target <- case uOpts of
     UpgradeInplace  -> Just <$> liftIO getExecutablePath
     (UpgradeAt p)   -> pure $ Just p
     UpgradeGHCupDir -> pure (Just (binDir </> "ghcup" <> exeExt))
 
   runUpgrade runAppState (do
-    v' <- liftE $ upgradeGHCup target force'
+    v' <- liftE $ upgradeGHCup target force' fatal
     GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
     pure (v', dls)
     ) >>= \case

app/ghcup/Main.hs

@@ -141,9 +141,7 @@ main = do
         )
   let listCommands = infoOption
         ("install set rm install-cabal list"
-#ifndef DISABLE_UPGRADE
           <> " upgrade"
-#endif
           <> " compile debug-info tool-requirements changelog"
         )
         (  long "list-commands"
@@ -245,14 +243,10 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                              alreadyInstalling' <- alreadyInstalling optCommand newTool
                              when (not alreadyInstalling') $
                                case t of
-#ifdef DISABLE_UPGRADE
-                                 GHCup -> pure ()
-#else
                                  GHCup -> runLogger $
                                             logWarn ("New GHCup version available: "
                                               <> prettyVer l
                                               <> ". To upgrade, run 'ghcup upgrade'")
-#endif
                                  _ -> runLogger $
                                         logWarn ("New "
                                           <> T.pack (prettyShow t)
@@ -307,9 +301,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
             Config configCommand       -> config configCommand settings keybindings runLogger
             Whereis whereisOptions
                     whereisCommand     -> whereis whereisCommand whereisOptions runAppState leanAppstate runLogger
-#ifndef DISABLE_UPGRADE
+            Upgrade uOpts force' fatal -> upgrade uOpts force' fatal dirs runAppState runLogger
-            Upgrade uOpts force'     -> upgrade uOpts force' dirs runAppState runLogger
-#endif
             ToolRequirements topts     -> toolRequirements topts runAppState runLogger
             ChangeLog changelogOpts    -> changelog changelogOpts runAppState runLogger
             Nuke                       -> nuke appState runLogger
@@ -353,9 +345,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
     (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer over)) ver
   alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = Left tver }))
     (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer tver)) ver
-#ifndef DISABLE_UPGRADE
+  alreadyInstalling (Upgrade _ _ _) (GHCup, _) = pure True
-  alreadyInstalling (Upgrade _ _) (GHCup, _) = pure True
-#endif
   alreadyInstalling _ _ = pure False
 
   cmp' :: ( HasLog env

docs/guide.md

@@ -57,6 +57,13 @@ as e.g. `/etc/bash_completion.d/ghcup` (depending on distro)
 and make sure your bashrc sources the startup script
 (`/usr/share/bash-completion/bash_completion` on some distros).
 
+## Portability
+
+`ghcup` is very portable. There are a few exceptions though:
+
+1. `ghcup tui` is only available on non-windows platforms
+2. legacy subcommands `ghcup install` (without a tool identifier) and `ghcup install-cabal` may be removed in the future
+
 # Configuration
 
 A configuration file can be put in `~/.ghcup/config.yaml`. The default config file

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>

docs/steps.md

@@ -16,6 +16,8 @@ The Glorious Glasgow Haskell Compilation System, version 8.10.7
 If this fails, consult [the Getting started page](../install) for information on
 how to install Haskell on your computer.
 
+This guide is partly based on [Gil Mizrahi's blog](https://gilmi.me/blog/post/2021/08/14/hs-core-tools).
+
 ## Compiling programs with ghc
 
 Running `ghc` invokes the Glasgow Haskell Compiler (GHC), and can be used to
@@ -326,6 +328,7 @@ see the [Cabal user guide](https://cabal.readthedocs.io/en/stable/getting-starte
 <a href="https://hackage.haskell.org/" class="btn btn-primary" role="button">Discover Haskell packages</a>
 <a href="https://hackage.haskell.org/package/base" class="btn btn-primary" role="button">The standard library</a>
 <a href="https://haskell-language-server.readthedocs.io/en/stable/installation.html" class="btn btn-primary" role="button">Editor setup with HLS</a>
+<a href="https://play-haskell.tomsmeding.com/play" class="btn btn-primary" role="button">Online playground</a>
 </div>
 
 ## How to learn Haskell proper

ghcup.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ghcup
-version:            0.1.17.6
+version:            0.1.17.8
 license:            LGPL-3.0-only
 license-file:       LICENSE
 copyright:          Julian Ospald 2020
@@ -48,13 +48,6 @@ flag no-exe
   default:     False
   manual:      True
 
-flag disable-upgrade
-  description:
-    Disable upgrade functionality. This is mainly to support brew packagers.
-
-  default:     False
-  manual:      True
-
 library
   exposed-modules:
     GHCup
@@ -204,6 +197,7 @@ executable ghcup
     GHCup.OptParse.Set
     GHCup.OptParse.ToolRequirements
     GHCup.OptParse.UnSet
+    GHCup.OptParse.Upgrade
     GHCup.OptParse.Whereis
 
   hs-source-dirs:     app/ghcup
@@ -277,11 +271,6 @@ executable ghcup
   if flag(no-exe)
     buildable: False
 
-  if flag(disable-upgrade)
-    cpp-options: -DDISABLE_UPGRADE
-
-  else
-    other-modules: GHCup.OptParse.Upgrade
 
 test-suite ghcup-test
   type:               exitcode-stdio-1.0

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
@@ -205,7 +205,7 @@ 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
@@ -215,12 +215,12 @@ installGHCBindist dlinfo ver isoFilepath forceInstall = do
   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
+  case installDir of
-    Just isoDir -> do                        -- isolated install
+    IsolateDir isoDir -> do                        -- isolated install
       lift $ logInfo $ "isolated installing GHC to " <> T.pack isoDir
-      liftE $ installPackedGHC dl (view dlSubdir dlinfo) isoDir ver forceInstall
+      liftE $ installPackedGHC dl (view dlSubdir dlinfo) (IsolateDirResolved isoDir) ver forceInstall
-    Nothing -> do                            -- regular install
+    GHCupInternal -> do                            -- regular install
-      liftE $ installPackedGHC dl (view dlSubdir dlinfo) ghcdir ver forceInstall
+      -- 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
@@ -299,7 +300,11 @@ installPackedGHC dl msubdir inst ver forceInstall = do
                    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)
 
 
@@ -316,10 +321,10 @@ installUnpackedGHC :: ( MonadReader env m
                       , MonadMask m
                       )
                    => FilePath            -- ^ Path to the unpacked GHC bindist (where the configure script resides)
-                   -> FilePath      -- ^ Path to install to
+                   -> InstallDirResolved  -- ^ Path to install to
                    -> Version             -- ^ The GHC version
                    -> Excepts '[ProcessError] m ()
-installUnpackedGHC path inst ver
+installUnpackedGHC path (fromInstallDir -> inst) ver
   | isWindows = do
       lift $ logInfo "Installing GHC (this may take a while)"
       -- Windows bindists are relocatable and don't need
@@ -369,7 +374,7 @@ 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 +392,9 @@ 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
@@ -408,7 +413,7 @@ installCabalBindist :: ( MonadMask m
                        )
                     => DownloadInfo
                     -> Version
-                    -> Maybe FilePath -- ^ isolated install filepath, if user provides any.
+                    -> InstallDir
                     -> Bool           -- ^ Force install
                     -> Excepts
                          '[ AlreadyInstalled
@@ -425,7 +430,7 @@ 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
@@ -437,12 +442,12 @@ 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
 
@@ -460,30 +465,33 @@ 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
+  case installDir of
-    Just isoDir -> do             -- isolated install
+    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
 
-    Nothing -> do                 -- regular install
+    GHCupInternal -> do                 -- regular install
-      liftE $ installCabalUnpacked workdir binDir (Just ver) forceInstall
+      liftE $ installCabalUnpacked workdir (GHCupDir binDir) ver forceInstall
 
 
 -- | Install an unpacked cabal distribution.Symbol
 installCabalUnpacked :: (MonadCatch m, HasLog env, MonadIO m, MonadReader env m)
               => FilePath      -- ^ Path to the unpacked cabal bindist (where the executable resides)
-              -> FilePath      -- ^ Path to install to
+              -> InstallDirResolved      -- ^ Path to install to
-              -> Maybe Version -- ^ Nothing for isolated install
+              -> 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)
@@ -510,7 +518,7 @@ installCabalBin :: ( MonadMask m
                    , MonadFail m
                    )
                 => Version
-                -> Maybe FilePath -- isolated install Path, if user provided any
+                -> InstallDir
                 -> Bool           -- force install
                 -> Excepts
                      '[ AlreadyInstalled
@@ -527,9 +535,9 @@ 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
@@ -548,7 +556,7 @@ installHLSBindist :: ( MonadMask m
                      )
                   => DownloadInfo
                   -> Version
-                  -> Maybe FilePath -- ^ isolated install path, if user passed any
+                  -> InstallDir -- ^ isolated install path, if user passed any
                   -> Bool       -- ^ Force install
                   -> Excepts
                        '[ AlreadyInstalled
@@ -567,7 +575,7 @@ 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
@@ -578,12 +586,12 @@ 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
 
@@ -604,22 +612,23 @@ 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
+  case installDir of
-    Just isoDir -> do
+    IsolateDir isoDir -> do
       lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
       if legacy
-      then liftE $ installHLSUnpackedLegacy workdir isoDir Nothing forceInstall
+      then liftE $ installHLSUnpackedLegacy workdir (IsolateDirResolved isoDir) ver forceInstall
-      else liftE $ runBuildAction tmpUnpack Nothing $ installHLSUnpacked workdir isoDir ver
+      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 +640,10 @@ 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 +651,13 @@ 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
+                         -> InstallDirResolved      -- ^ Path to install to
-                         -> Maybe Version -- ^ Nothing for isolated install
+                         -> 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
@@ -659,11 +668,14 @@ 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)
@@ -676,10 +688,13 @@ 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)
@@ -708,7 +723,7 @@ installHLSBin :: ( MonadMask m
                  , MonadFail m
                  )
               => Version
-              -> Maybe FilePath  -- isolated install Dir (if any)
+              -> InstallDir
               -> Bool            -- force install
               -> Excepts
                    '[ AlreadyInstalled
@@ -727,9 +742,9 @@ 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 +764,7 @@ compileHLS :: ( MonadMask m
            -> [Version]
            -> Maybe Int
            -> Maybe Version
-           -> Maybe FilePath
+           -> InstallDir
            -> Maybe (Either FilePath URI)
            -> Maybe URI
            -> Maybe (Either FilePath [URI])  -- ^ patches
@@ -764,7 +779,7 @@ 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
@@ -837,8 +852,8 @@ 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"
+      let tmpInstallDir = workdir </> "out"
-      liftIO $ createDirRecursive' installDir
+      liftIO $ createDirRecursive' tmpInstallDir
 
       -- apply patches
       liftE $ applyAnyPatch patches workdir
@@ -861,8 +876,8 @@ 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)
+        let ghcInstallDir = tmpInstallDir </> T.unpack (prettyVer ghc)
-        liftIO $ createDirRecursive' installDir
+        liftIO $ createDirRecursive' tmpInstallDir
         lift $ logInfo $ "Building HLS " <> prettyVer installVer <> " for GHC version " <> prettyVer ghc
         liftE $ lEM @_ @'[ProcessError] $
           execLogged "cabal" ( [ "v2-install"
@@ -885,17 +900,17 @@ 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
+      case installDir of
-        Just isoDir -> do
+        IsolateDir isoDir -> do
           lift $ logInfo $ "isolated installing HLS to " <> T.pack isoDir
-          liftE $ installHLSUnpackedLegacy installDir isoDir Nothing True
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (IsolateDirResolved isoDir) installVer True
-        Nothing -> do
+        GHCupInternal -> do
-          liftE $ installHLSUnpackedLegacy installDir binDir (Just installVer) True
+          liftE $ installHLSUnpackedLegacy tmpInstallDir (GHCupDir binDir) installVer True
     )
 
   pure installVer
@@ -919,7 +934,7 @@ installStackBin :: ( MonadMask m
                    , MonadFail m
                    )
                 => Version
-                -> Maybe FilePath  -- ^ isolate install Dir (if any)
+                -> InstallDir
                 -> Bool            -- ^ Force install
                 -> Excepts
                      '[ AlreadyInstalled
@@ -936,9 +951,9 @@ 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 +972,7 @@ installStackBindist :: ( MonadMask m
                        )
                     => DownloadInfo
                     -> Version
-                    -> Maybe FilePath -- ^ isolate install Dir (if any)
+                    -> InstallDir
                     -> Bool           -- ^ Force install
                     -> Excepts
                          '[ AlreadyInstalled
@@ -974,7 +989,7 @@ 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 +1000,12 @@ 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
 
@@ -1007,29 +1022,32 @@ 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
+  case installDir of
-    Just isoDir -> do                 -- isolated install
+    IsolateDir isoDir -> do                 -- isolated install
       lift $ logInfo $ "isolated installing Stack to " <> T.pack isoDir
-      liftE $ installStackUnpacked workdir isoDir Nothing forceInstall
+      liftE $ installStackUnpacked workdir (IsolateDirResolved isoDir) ver forceInstall
-    Nothing -> do                     -- regular install
+    GHCupInternal -> do                     -- regular install
-      liftE $ installStackUnpacked workdir binDir (Just ver) forceInstall
+      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
+              -> InstallDirResolved
-              -> Maybe Version -- ^ Nothing for isolated installs
+              -> 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)
@@ -1223,7 +1241,7 @@ 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 ()
@@ -2121,7 +2139,7 @@ compileGHC :: ( MonadMask m
            -> [Text]                   -- ^ additional args to ./configure
            -> Maybe String             -- ^ build flavour
            -> Bool
-           -> Maybe FilePath           -- ^ isolate dir
+           -> InstallDir
            -> Excepts
                 '[ AlreadyInstalled
                  , BuildFailed
@@ -2146,7 +2164,7 @@ 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
@@ -2219,18 +2237,18 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
     alreadySet <- fmap (== Just installVer) $ lift $ ghcSet (_tvTarget installVer)
 
     when alreadyInstalled $ do
-      case isolateDir of
+      case installDir of
-        Just isoDir ->
+        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
+    ghcdir <- case installDir of
-      Just isoDir -> pure isoDir
+      IsolateDir isoDir -> pure $ IsolateDirResolved isoDir
-      Nothing -> lift $ ghcupGHCDir installVer
+      GHCupInternal -> GHCupDir <$> lift (ghcupGHCDir installVer)
 
     (mBindist, bmk) <- liftE $ runBuildAction
       tmpUnpack
@@ -2243,8 +2261,8 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
         pure (b, bmk)
       )
 
-    case isolateDir of
+    case installDir of
-      Nothing ->
+      GHCupInternal ->
         -- only remove old ghc in regular installs
         when alreadyInstalled $ do
           lift $ logInfo "Deleting existing installation"
@@ -2259,11 +2277,11 @@ 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
+    liftIO $ B.writeFile (fromInstallDir ghcdir </> ghcUpSrcBuiltFile) bmk
 
-    case isolateDir of
+    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
@@ -2292,7 +2310,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                            )
                         => GHCTargetVersion
                         -> FilePath
-                        -> FilePath
+                        -> InstallDirResolved
                         -> Excepts
                              '[ FileDoesNotExistError
                               , HadrianNotFound
@@ -2351,7 +2369,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                         )
                      => GHCTargetVersion
                      -> FilePath
-                     -> FilePath
+                     -> InstallDirResolved
                      -> Excepts
                           '[ FileDoesNotExistError
                            , HadrianNotFound
@@ -2486,7 +2504,7 @@ compileGHC targetGhc ov bstrap jobs mbuildConfig patches aargs buildFlavour hadr
                       )
                    => GHCTargetVersion
                    -> FilePath
-                   -> FilePath
+                   -> InstallDirResolved
                    -> Excepts
                         '[ FileDoesNotExistError
                          , InvalidBuildConfig
@@ -2497,7 +2515,7 @@ 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
@@ -2587,6 +2605,7 @@ upgradeGHCup :: ( MonadMask m
              => Maybe FilePath    -- ^ full file destination to write ghcup into
              -> Bool              -- ^ whether to force update regardless
                                   --   of currently installed version
+             -> Bool              -- ^ whether to throw an error if ghcup is shadowed
              -> Excepts
                   '[ CopyError
                    , DigestError
@@ -2595,15 +2614,16 @@ upgradeGHCup :: ( MonadMask m
                    , DownloadFailed
                    , NoDownload
                    , NoUpdate
+                   , GHCupShadowed
                    ]
                   m
                   Version
-upgradeGHCup mtarget force' = do
+upgradeGHCup mtarget force' fatal = do
   Dirs {..} <- lift getDirs
   GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
 
   lift $ logInfo "Upgrading GHCup..."
-  let latestVer = fromJust $ fst <$> getLatest dls GHCup
+  let latestVer = fst (fromJust (getLatest dls GHCup))
   (Just ghcupPVPVer) <- pure $ pvpToVersion ghcUpVer ""
   when (not force' && (latestVer <= ghcupPVPVer)) $ throwE NoUpdate
   dli   <- liftE $ getDownloadInfo GHCup latestVer
@@ -2625,14 +2645,17 @@ upgradeGHCup mtarget force' = do
     lift $ logWarn $ T.pack (takeFileName destFile) <> " is not in PATH! You have to add it in order to use ghcup."
   liftIO (isShadowed destFile) >>= \case
     Nothing -> pure ()
-    Just pa -> lift $ logWarn $ "ghcup is shadowed by "
+    Just pa
+      | fatal -> throwE (GHCupShadowed pa destFile latestVer)
+      | otherwise ->
+        lift $ logWarn $ "ghcup is shadowed by "
           <> T.pack pa
           <> ". The upgrade will not be in effect, unless you remove "
           <> T.pack pa
           <> " or make sure "
           <> T.pack destDir
           <> " comes before "
-      <> T.pack (takeFileName pa)
+          <> T.pack (takeDirectory pa)
           <> " in PATH."
 
   pure latestVer

lib/GHCup/Errors.hs

@@ -27,6 +27,7 @@ import           Data.CaseInsensitive           ( CI )
 import           Data.Text                      ( Text )
 import           Data.Versions
 import           Haskus.Utils.Variant
+import           System.FilePath
 import           Text.PrettyPrint               hiding ( (<>) )
 import           Text.PrettyPrint.HughesPJClass hiding ( (<>) )
 import           URI.ByteString
@@ -291,6 +292,24 @@ instance Pretty HadrianNotFound where
   pPrint HadrianNotFound =
     text "Could not find Hadrian build files. Does this GHC version support Hadrian builds?"
 
+data GHCupShadowed = GHCupShadowed
+                       FilePath  -- shadow binary
+                       FilePath  -- upgraded binary
+                       Version   -- upgraded version
+  deriving Show
+
+instance Pretty GHCupShadowed where
+  pPrint (GHCupShadowed sh up _) =
+    text ("ghcup is shadowed by "
+         <> sh
+         <> ". The upgrade will not be in effect, unless you remove "
+         <> sh
+         <> " or make sure "
+         <> takeDirectory up
+         <> " comes before "
+         <> takeDirectory sh
+         <> " in PATH."
+         )
 
     -------------------------
     --[ High-level errors ]--

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

@@ -317,10 +317,10 @@ ghcSet mtarget = do
            MP.setInput rest
            pure x
          )
-        <* pathSep
+        <* MP.some pathSep
         <* MP.takeRest
         <* MP.eof
-    ghcSubPath = pathSep <* MP.chunk "ghc" *> pathSep
+    ghcSubPath = MP.some pathSep <* MP.chunk "ghc" *> MP.some pathSep
 
 -- | Get all installed GHCs by reading ~/.ghcup/ghc/<dir>.
 -- If a dir cannot be parsed, returns left.
@@ -398,10 +398,10 @@ cabalSet = do
   cabalParse = MP.chunk "cabal-" *> version'
   -- parses any path component ending with path separator,
   -- e.g. "foo/"
-  stripPathComponet = parseUntil1 pathSep *> pathSep
+  stripPathComponet = parseUntil1 pathSep *> MP.some pathSep
   -- parses an absolute path up until the last path separator,
   -- e.g. "/bar/baz/foo" -> "/bar/baz/", leaving "foo"
-  stripAbsolutePath = pathSep *> MP.many (MP.try stripPathComponet)
+  stripAbsolutePath = MP.some pathSep *> MP.many (MP.try stripPathComponet)
   -- parses a relative path up until the last path separator,
   -- e.g. "bar/baz/foo" -> "bar/baz/", leaving "foo"
   stripRelativePath = MP.many (MP.try stripPathComponet)
@@ -492,10 +492,10 @@ stackSet = do
     cabalParse = MP.chunk "stack-" *> version'
     -- parses any path component ending with path separator,
     -- e.g. "foo/"
-    stripPathComponet = parseUntil1 pathSep *> pathSep
+    stripPathComponet = parseUntil1 pathSep *> MP.some pathSep
     -- parses an absolute path up until the last path separator,
     -- e.g. "/bar/baz/foo" -> "/bar/baz/", leaving "foo"
-    stripAbsolutePath = pathSep *> MP.many (MP.try stripPathComponet)
+    stripAbsolutePath = MP.some pathSep *> MP.many (MP.try stripPathComponet)
     -- parses a relative path up until the last path separator,
     -- e.g. "bar/baz/foo" -> "bar/baz/", leaving "foo"
     stripRelativePath = MP.many (MP.try stripPathComponet)
@@ -543,10 +543,10 @@ hlsSet = do
     cabalParse = MP.chunk "haskell-language-server-wrapper-" *> version'
     -- parses any path component ending with path separator,
     -- e.g. "foo/"
-    stripPathComponet = parseUntil1 pathSep *> pathSep
+    stripPathComponet = parseUntil1 pathSep *> MP.some pathSep
     -- parses an absolute path up until the last path separator,
     -- e.g. "/bar/baz/foo" -> "/bar/baz/", leaving "foo"
-    stripAbsolutePath = pathSep *> MP.many (MP.try stripPathComponet)
+    stripAbsolutePath = MP.some pathSep *> MP.many (MP.try stripPathComponet)
     -- parses a relative path up until the last path separator,
     -- e.g. "bar/baz/foo" -> "bar/baz/", leaving "foo"
     stripRelativePath = MP.many (MP.try stripPathComponet)
@@ -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

@@ -16,6 +16,7 @@
 #   * BOOTSTRAP_HASKELL_INSTALL_HLS - whether to install latest hls
 #   * BOOTSTRAP_HASKELL_ADJUST_BASHRC - whether to adjust PATH in bashrc (prepend)
 #   * BOOTSTRAP_HASKELL_ADJUST_CABAL_CONFIG - whether to adjust mingw paths in cabal.config on windows
+#   * GHCUP_BASE_URL - the base url for ghcup binary download (use this to overwrite https://downloads.haskell.org/~ghcup with a mirror)
 
 # License: LGPL-3.0
 
@@ -25,8 +26,8 @@
 
 plat="$(uname -s)"
 arch=$(uname -m)
-ghver="0.1.17.6"
+ghver="0.1.17.7"
-base_url="https://downloads.haskell.org/~ghcup"
+: "${GHCUP_BASE_URL:=https://downloads.haskell.org/~ghcup}"
 
 export GHCUP_SKIP_UPDATE_CHECK=yes
 
@@ -235,26 +236,26 @@ download_ghcup() {
 					# we could be in a 32bit docker container, in which
 					# case uname doesn't give us what we want
 					if [ "$(getconf LONG_BIT)" = "32" ] ; then
-						_url=${base_url}/${ghver}/i386-linux-ghcup-${ghver}
+						_url=${GHCUP_BASE_URL}/${ghver}/i386-linux-ghcup-${ghver}
 					elif [ "$(getconf LONG_BIT)" = "64" ] ; then
-						_url=${base_url}/${ghver}/x86_64-linux-ghcup-${ghver}
+						_url=${GHCUP_BASE_URL}/${ghver}/x86_64-linux-ghcup-${ghver}
 					else
 						die "Unknown long bit size: $(getconf LONG_BIT)"
 					fi
 					;;
 				i*86)
-					_url=${base_url}/${ghver}/i386-linux-ghcup-${ghver}
+					_url=${GHCUP_BASE_URL}/${ghver}/i386-linux-ghcup-${ghver}
 					;;
 				armv7*|*armv8l*)
-					_url=${base_url}/${ghver}/armv7-linux-ghcup-${ghver}
+					_url=${GHCUP_BASE_URL}/${ghver}/armv7-linux-ghcup-${ghver}
 					;;
 				aarch64|arm64)
 					# we could be in a 32bit docker container, in which
 					# case uname doesn't give us what we want
 					if [ "$(getconf LONG_BIT)" = "32" ] ; then
-						_url=${base_url}/${ghver}/armv7-linux-ghcup-${ghver}
+						_url=${GHCUP_BASE_URL}/${ghver}/armv7-linux-ghcup-${ghver}
 					elif [ "$(getconf LONG_BIT)" = "64" ] ; then
-						_url=${base_url}/${ghver}/aarch64-linux-ghcup-${ghver}
+						_url=${GHCUP_BASE_URL}/${ghver}/aarch64-linux-ghcup-${ghver}
 					else
 						die "Unknown long bit size: $(getconf LONG_BIT)"
 					fi
@@ -281,15 +282,15 @@ download_ghcup() {
 				*) die "Unknown architecture: ${arch}"
 					;;
 			esac
-			_url=${base_url}/${ghver}/x86_64-freebsd${freebsd_ver}-ghcup-${ghver}
+			_url=${GHCUP_BASE_URL}/${ghver}/x86_64-freebsd${freebsd_ver}-ghcup-${ghver}
             ;;
         "Darwin"|"darwin")
 			case "${arch}" in
 				x86_64|amd64)
-					_url=${base_url}/${ghver}/x86_64-apple-darwin-ghcup-${ghver}
+					_url=${GHCUP_BASE_URL}/${ghver}/x86_64-apple-darwin-ghcup-${ghver}
 					;;
 				aarch64|arm64|armv8l)
-					_url=${base_url}/${ghver}/aarch64-apple-darwin-ghcup-${ghver}
+					_url=${GHCUP_BASE_URL}/${ghver}/aarch64-apple-darwin-ghcup-${ghver}
 					;;
 				i*86)
 					die "i386 currently not supported!"
@@ -301,7 +302,7 @@ download_ghcup() {
         MSYS*|MINGW*)
 			case "${arch}" in
 				x86_64|amd64)
-					_url=${base_url}/${ghver}/x86_64-mingw64-ghcup-${ghver}.exe
+					_url=${GHCUP_BASE_URL}/${ghver}/x86_64-mingw64-ghcup-${ghver}.exe
 					;;
 				*) die "Unknown architecture: ${arch}"
 					;;

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:
   - .