Fix disabling installation of stack

Fixes #429

CHANGELOG.md

@@ -1,5 +1,36 @@
 # Revision history for ghcup
 
+## 0.1.18.1 -- 2022-08-06
+
+* fix sdist and unbreak hackage, wrt [#399](https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/399)
+
+## 0.1.18.0 -- 2022-07-30
+
+* Fix tui set wrt [#266](https://gitlab.haskell.org/haskell/ghcup-hs/-/merge_requests/266) by Arjun Kathuria
+    - Ask the user to install the tool via prompt when setting an non-installed version
+* improvements to safe (un-)installations
+    - bindists that don't support `make DESTDIR=/some/tmp/dir install` are now unsupported
+    - installed GHC files are now recorded to avoid use of `removePathForcibly`
+    - internally uses a newtype wrapper for user-input paths and restrict destructive operations to validated paths
+* Add `--disable-ld-override` for darwin bindists wrt #391
+* Allow passing bindist configure args wrt #377
+* use of `TMPDIR` is dropped... now uses an internal tmp dir `~/.ghcup/tmp`
+* improvements to error handling and warnings
+* Require --isolate to have an absolute directory, fixes #367
+* Fix mingw PATH handling wrt #371
+* Add --mingw-path switch to `ghcup run`
+* Fix `ghcup run` on windows, fixes #375
+* Improve `ghcup compile <hls|ghc>`
+    - short hashes now work
+    - print the long hash in addition to the detected version
+* Improve `ghcup compile hls`
+    - add `--git-describe-version` switch as an alternative to `--overwrite-version`
+    - Allow to build HLS from hackage (now is the default)
+	- Allow to run 'cabal update' automatically before the HLS build
+	- Fix parser and completer for 'ghcup compile hls --version'
+* Improve `ghcup compile ghc`
+    - Allow to build from arbitrary GHC source dists
+
 ## 0.1.17.10 -- 2022-05-12
 
 * windows hotfix (hackage-only release)

app/ghcup/BrickMain.hs

@@ -17,6 +17,7 @@ import           GHCup.Prelude ( decUTF8Safe )
 import           GHCup.Prelude.File
 import           GHCup.Prelude.Logger
 import           GHCup.Prelude.Process
+import           GHCup.Prompts
 
 import           Brick
 import           Brick.Widgets.Border
@@ -52,6 +53,8 @@ import           Text.PrettyPrint.HughesPJClass ( prettyShow )
 import           URI.ByteString
 
 import qualified Data.Text                     as T
+import qualified Data.Text.Lazy.Builder        as B
+import qualified Data.Text.Lazy                as L
 import qualified Graphics.Vty                  as Vty
 import qualified Data.Vector                   as V
 import System.Environment (getExecutablePath)
@@ -98,7 +101,7 @@ keyHandlers KeyBindings {..} =
   [ (bQuit, const "Quit"     , halt)
   , (bInstall, const "Install"  , withIOAction install')
   , (bUninstall, const "Uninstall", withIOAction del')
-  , (bSet, const "Set"      , withIOAction ((liftIO .) . set'))
+  , (bSet, const "Set"      , withIOAction set')
   , (bChangelog, const "ChangeLog", withIOAction changelog')
   , ( bShowAllVersions
     , \BrickSettings {..} ->
@@ -486,9 +489,12 @@ install' _ (_, ListResult {..}) = do
             <> "Also check the logs in ~/.ghcup/logs"
 
 
-set' :: BrickState -> (Int, ListResult) -> IO (Either String ())
+set' :: (MonadReader AppState m, MonadIO m, MonadThrow m, MonadFail m, MonadMask m, MonadUnliftIO m)
-set' _ (_, ListResult {..}) = do
+     => BrickState
-  settings <- readIORef settings'
+     -> (Int, ListResult)
+     -> m (Either String ())
+set' bs input@(_, ListResult {..}) = do
+  settings <- liftIO $ readIORef settings'
 
   let run =
         flip runReaderT settings
@@ -504,7 +510,28 @@ set' _ (_, ListResult {..}) = do
     )
     >>= \case
           VRight _ -> pure $ Right ()
-          VLeft  e -> pure $ Left (prettyShow e)
+          VLeft  e -> case e of
+            (V (NotInstalled tool _)) -> do
+              promptAnswer <- getUserPromptResponse userPrompt
+              case promptAnswer of
+                PromptYes -> do
+                  res <- install' bs input
+                  case res of
+                    (Left err) -> pure $ Left err
+                    (Right _) -> do
+                      logInfo "Setting now..."
+                      set' bs input
+
+                PromptNo -> pure $ Left (prettyShow e)
+              where
+                userPrompt = L.toStrict . B.toLazyText . B.fromString $
+                  "This Version of "
+                  <> show tool
+                  <> " you are trying to set is not installed.\n"
+                  <> "Would you like to install it first? [Y/N]: "
+
+            _ -> pure $ Left (prettyShow e)
+
 
 
 del' :: (MonadReader AppState m, MonadIO m, MonadFail m, MonadMask m, MonadUnliftIO m)

app/ghcup/GHCup/OptParse/ChangeLog.hs

@@ -58,7 +58,7 @@ data ChangeLogOptions = ChangeLogOptions
     --[ Parsers ]--
     ---------------
 
-          
+
 changelogP :: Parser ChangeLogOptions
 changelogP =
   (\x y -> ChangeLogOptions x y)
@@ -71,15 +71,16 @@ changelogP =
                 "cabal" -> Right Cabal
                 "ghcup" -> Right GHCup
                 "stack" -> Right Stack
+                "hls"   -> Right HLS
                 e       -> Left e
               )
             )
-            (short 't' <> long "tool" <> metavar "<ghc|cabal|ghcup>" <> help
+            (short 't' <> long "tool" <> metavar "<ghc|cabal|hls|ghcup>" <> help
               "Open changelog for given tool (default: ghc)"
               <> completer toolCompleter
             )
           )
-    <*> optional (toolVersionArgument Nothing Nothing)
+    <*> optional (toolVersionTagArgument Nothing Nothing)
 
 
 
@@ -116,7 +117,8 @@ changelog ChangeLogOptions{..} runAppState runLogger = do
       ver' = maybe
         (Right Latest)
         (\case
-          ToolVersion tv -> Left (_tvVersion tv) -- FIXME: ugly sharing of ToolVersion
+          GHCVersion tv  -> Left (_tvVersion tv)
+          ToolVersion tv -> Left tv
           ToolTag     t  -> Right t
         )
         clToolVer

app/ghcup/GHCup/OptParse/Common.hs

@@ -70,20 +70,24 @@ import Control.Exception (evaluate)
     --[ Types ]--
     -------------
 
-data ToolVersion = ToolVersion GHCTargetVersion -- target is ignored for cabal
+data ToolVersion = GHCVersion GHCTargetVersion
+                 | ToolVersion Version
                  | ToolTag Tag
 
 -- a superset of ToolVersion
-data SetToolVersion = SetToolVersion GHCTargetVersion
+data SetToolVersion = SetGHCVersion GHCTargetVersion
+                    | SetToolVersion Version
                     | SetToolTag Tag
                     | SetRecommended
                     | SetNext
 
 prettyToolVer :: ToolVersion -> String
-prettyToolVer (ToolVersion v') = T.unpack $ tVerToText v'
+prettyToolVer (GHCVersion v') = T.unpack $ tVerToText v'
+prettyToolVer (ToolVersion v') = T.unpack $ prettyVer v'
 prettyToolVer (ToolTag t) = show t
 
 toSetToolVer :: Maybe ToolVersion -> SetToolVersion
+toSetToolVer (Just (GHCVersion v')) = SetGHCVersion v'
 toSetToolVer (Just (ToolVersion v')) = SetToolVersion v'
 toSetToolVer (Just (ToolTag t')) = SetToolTag t'
 toSetToolVer Nothing = SetRecommended
@@ -96,10 +100,9 @@ toSetToolVer Nothing = SetRecommended
     --------------
 
 
--- | same as toolVersionParser, except as an argument.
+toolVersionTagArgument :: Maybe ListCriteria -> Maybe Tool -> Parser ToolVersion
-toolVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser ToolVersion
+toolVersionTagArgument criteria tool =
-toolVersionArgument criteria tool =
+  argument (eitherReader (parser tool))
-  argument (eitherReader toolVersionEither)
     (metavar (mv tool)
     <> completer (tagCompleter (fromMaybe GHC tool) [])
     <> foldMap (completer . versionCompleter criteria) tool)
@@ -108,20 +111,19 @@ toolVersionArgument criteria tool =
   mv (Just HLS) = "HLS_VERSION|TAG"
   mv _          = "VERSION|TAG"
 
+  parser (Just GHC) = ghcVersionTagEither
+  parser Nothing    = ghcVersionTagEither
+  parser _          = toolVersionTagEither
 
-versionParser :: Parser GHCTargetVersion
-versionParser = option
-  (eitherReader tVersionEither)
-  (short 'v' <> long "version" <> metavar "VERSION" <> help "The target version"
-  )
 
 versionParser' :: Maybe ListCriteria -> Maybe Tool -> Parser Version
 versionParser' criteria tool = argument
   (eitherReader (first show . version . T.pack))
   (metavar "VERSION"  <> foldMap (completer . versionCompleter criteria) tool)
 
-versionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser GHCTargetVersion
+ghcVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser GHCTargetVersion
-versionArgument criteria tool = argument (eitherReader tVersionEither) (metavar "VERSION" <> foldMap (completer . versionCompleter criteria) tool)
+ghcVersionArgument criteria tool = argument (eitherReader ghcVersionEither)
+                                            (metavar "VERSION" <> foldMap (completer . versionCompleter criteria) tool)
 
 
 -- https://github.com/pcapriotti/optparse-applicative/issues/148
@@ -230,9 +232,15 @@ isolateParser f = case isValid f && isAbsolute f of
               True -> Right $ normalise f
               False -> Left "Please enter a valid filepath for isolate dir."
 
-toolVersionEither :: String -> Either String ToolVersion
+-- this accepts cross prefix
-toolVersionEither s' =
+ghcVersionTagEither :: String -> Either String ToolVersion
-  second ToolTag (tagEither s') <|> second ToolVersion (tVersionEither s')
+ghcVersionTagEither s' =
+  second ToolTag (tagEither s') <|> second GHCVersion (ghcVersionEither s')
+
+-- this ignores cross prefix
+toolVersionTagEither :: String -> Either String ToolVersion
+toolVersionTagEither s' =
+  second ToolTag (tagEither s') <|> second ToolVersion (toolVersionEither s')
 
 tagEither :: String -> Either String Tag
 tagEither s' = case fmap toLower s' of
@@ -244,10 +252,14 @@ tagEither s' = case fmap toLower s' of
   other         -> Left $ "Unknown tag " <> other
 
 
-tVersionEither :: String -> Either String GHCTargetVersion
+ghcVersionEither :: String -> Either String GHCTargetVersion
-tVersionEither =
+ghcVersionEither =
   first (const "Not a valid version") . MP.parse ghcTargetVerP "" . T.pack
 
+toolVersionEither :: String -> Either String Version
+toolVersionEither =
+  first (const "Not a valid version") . MP.parse version' "" . T.pack
+
 
 toolParser :: String -> Either String Tool
 toolParser s' | t == T.pack "ghc"   = Right GHC
@@ -665,7 +677,7 @@ fromVersion' SetRecommended tool = do
   GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
   bimap mkTVer Just <$> getRecommended dls tool
     ?? TagNotFound Recommended tool
-fromVersion' (SetToolVersion v) tool = do
+fromVersion' (SetGHCVersion v) tool = do
   GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
   let vi = getVersionInfo (_tvVersion v) tool dls
   case pvp $ prettyVer (_tvVersion v) of -- need to be strict here
@@ -677,6 +689,18 @@ fromVersion' (SetToolVersion v) tool = do
           when (v' /= _tvVersion v) $ lift $ logWarn ("Assuming you meant version " <> prettyVer v')
           pure (GHCTargetVersion (_tvTarget v) v', Just vi')
         Nothing -> pure (v, vi)
+fromVersion' (SetToolVersion v) tool = do
+  GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
+  let vi = getVersionInfo v tool dls
+  case pvp $ prettyVer v of -- need to be strict here
+    Left _ -> pure (mkTVer v, vi)
+    Right pvpIn ->
+      lift (getLatestToolFor tool pvpIn dls) >>= \case
+        Just (pvp_, vi') -> do
+          v' <- lift $ pvpToVersion pvp_ ""
+          when (v' /= v) $ lift $ logWarn ("Assuming you meant version " <> prettyVer v')
+          pure (GHCTargetVersion mempty v', Just vi')
+        Nothing -> pure (mkTVer v, vi)
 fromVersion' (SetToolTag Latest) tool = do
   GHCupInfo { _ghcupDownloads = dls } <- lift getGHCupInfo
   bimap mkTVer Just <$> getLatest dls tool ?? TagNotFound Latest tool

app/ghcup/GHCup/OptParse/Compile.hs

@@ -401,7 +401,7 @@ hlsCompileOpts =
           )
         )
     <*> some (
-          option (eitherReader toolVersionEither)
+          option (eitherReader ghcVersionTagEither)
             (  long "ghc" <> metavar "GHC_VERSION|TAG" <> help "For which GHC version to compile for (can be specified multiple times)"
             <> completer (tagCompleter GHC [])
             <> completer (versionCompleter Nothing GHC))

app/ghcup/GHCup/OptParse/Install.hs

@@ -171,7 +171,7 @@ Examples:
   ghcup install ghc 8.10.2
 
   # install GHC head fedora bindist
-  ghcup install ghc -u https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27 head|]
+  ghcup install ghc -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head|]
 
 
 installOpts :: Maybe Tool -> Parser InstallOptions
@@ -196,7 +196,7 @@ installOpts tool =
                       <> completer (toolDlCompleter (fromMaybe GHC tool))
                     )
                   )
-            <*> (Just <$> toolVersionArgument Nothing tool)
+            <*> (Just <$> toolVersionTagArgument Nothing tool)
             )
         <|> pure (Nothing, Nothing)
         )
@@ -546,4 +546,3 @@ install installCommand settings getAppState' runLogger = case installCommand of
                 logError $ T.pack $ prettyShow e
                 logError $ "Also check the logs in " <> T.pack (fromGHCupPath logsDir)
               pure $ ExitFailure 4
-

app/ghcup/GHCup/OptParse/Prefetch.hs

@@ -74,44 +74,44 @@ data PrefetchGHCOptions = PrefetchGHCOptions {
     --[ Parsers ]--
     ---------------
 
-          
+
 prefetchP :: Parser PrefetchCommand
 prefetchP = subparser
   (  command
       "ghc"
-      (info 
+      (info
         (PrefetchGHC
           <$> (PrefetchGHCOptions
                 <$> ( switch (short 's' <> long "source" <> help "Download source tarball instead of bindist") <**> helper )
                 <*> optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*>  optional (toolVersionArgument Nothing (Just GHC)) )
+          <*>  optional (toolVersionTagArgument Nothing (Just GHC)) )
         ( progDesc "Download GHC assets for installation")
       )
       <>
      command
       "cabal"
-      (info 
+      (info
         (PrefetchCabal
           <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just Cabal)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just Cabal)) <**> helper ))
         ( progDesc "Download cabal assets for installation")
       )
       <>
      command
       "hls"
-      (info 
+      (info
         (PrefetchHLS
           <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just HLS)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just HLS)) <**> helper ))
         ( progDesc "Download HLS assets for installation")
       )
       <>
      command
       "stack"
-      (info 
+      (info
         (PrefetchStack
           <$> fmap PrefetchOptions (optional (option str (short 'd' <> long "directory" <> help "directory to download into (default: ~/.ghcup/cache/)" <> completer (bashCompleter "directory"))))
-          <*> ( optional (toolVersionArgument Nothing (Just Stack)) <**> helper ))
+          <*> ( optional (toolVersionTagArgument Nothing (Just Stack)) <**> helper ))
         ( progDesc "Download stack assets for installation")
       )
       <>

app/ghcup/GHCup/OptParse/Rm.hs

@@ -71,7 +71,7 @@ data RmOptions = RmOptions
     --[ Parsers ]--
     ---------------
 
-          
+
 rmParser :: Parser (Either RmCommand RmOptions)
 rmParser =
   (Left <$> subparser
@@ -103,7 +103,7 @@ rmParser =
 
 
 rmOpts :: Maybe Tool -> Parser RmOptions
-rmOpts tool = RmOptions <$> versionArgument (Just ListInstalled) tool
+rmOpts tool = RmOptions <$> ghcVersionArgument (Just ListInstalled) tool
 
 
 

app/ghcup/GHCup/OptParse/Run.hs

@@ -5,6 +5,7 @@
 {-# LANGUAGE RankNTypes        #-}
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE ViewPatterns      #-}
 module GHCup.OptParse.Run where
 
 
@@ -46,6 +47,7 @@ import qualified Data.Text                     as T
 #ifndef IS_WINDOWS
 import qualified System.Posix.Process          as SPP
 #endif
+import Data.Versions ( prettyVer, Version )
 
 
 
@@ -88,7 +90,7 @@ runOpts =
           (short 'm' <> long "mingw-path" <> help "On windows, add mingw64 PATHs to environment (does nothing on unix)")
     <*> optional
           (option
-            (eitherReader toolVersionEither)
+            (eitherReader ghcVersionTagEither)
             (metavar "GHC_VERSION" <> long "ghc" <> help "The ghc version"
             <> completer (tagCompleter GHC [])
             <> (completer $ versionCompleter Nothing GHC)
@@ -96,7 +98,7 @@ runOpts =
           )
     <*> optional
           (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
             (metavar "CABAL_VERSION" <> long "cabal" <> help "The cabal version"
             <> completer (tagCompleter Cabal [])
             <> (completer $ versionCompleter Nothing Cabal)
@@ -104,7 +106,7 @@ runOpts =
           )
     <*> optional
           (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
             (metavar "HLS_VERSION" <> long "hls" <> help "The HLS version"
             <> completer (tagCompleter HLS [])
             <> (completer $ versionCompleter Nothing HLS)
@@ -112,7 +114,7 @@ runOpts =
           )
     <*> optional
           (option
-            (eitherReader toolVersionEither)
+            (eitherReader toolVersionTagEither)
             (metavar "STACK_VERSION" <> long "stack" <> help "The stack version"
             <> completer (tagCompleter Stack [])
             <> (completer $ versionCompleter Nothing Stack)
@@ -217,7 +219,7 @@ runRUN appState action' = do
 
 
 
-run :: forall m. 
+run :: forall m .
        ( MonadFail m
        , MonadMask m
        , MonadCatch m
@@ -233,12 +235,16 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
    r <- if not runQuick
         then runRUN runAppState $ do
          toolchain <- liftE resolveToolchainFull
-         tmp <- liftIO $ createTmpDir toolchain
+
+         -- oh dear
+         r <- lift ask
+         tmp <- lift . lift . lift . flip runReaderT (fromAppState r) $ createTmpDir toolchain
+
          liftE $ installToolChainFull toolchain tmp
          pure tmp
         else runLeanRUN leanAppstate $ do
          toolchain <- resolveToolchain
-         tmp <- liftIO $ createTmpDir toolchain
+         tmp <- lift $ createTmpDir toolchain
          liftE $ installToolChain toolchain tmp
          pure tmp
    case r of
@@ -268,17 +274,6 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
 
   where
 
-   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
                            , MonadThrow m
@@ -296,29 +291,33 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
            pure v
          cabalVer <- forM runCabalVer $ \ver -> do
            (v, _) <- liftE $ fromVersion (Just ver) Cabal
-           pure v
+           pure (_tvVersion v)
          hlsVer <- forM runHLSVer $ \ver -> do
            (v, _) <- liftE $ fromVersion (Just ver) HLS
-           pure v
+           pure (_tvVersion v)
          stackVer <- forM runStackVer $ \ver -> do
            (v, _) <- liftE $ fromVersion (Just ver) Stack
-           pure v
+           pure (_tvVersion v)
          pure Toolchain{..}
 
    resolveToolchain = do
          ghcVer <- case runGHCVer of
-            Just (ToolVersion v) -> pure $ Just v
+            Just (GHCVersion v) -> pure $ Just v
+            Just (ToolVersion v) -> pure $ Just (mkTVer v)
             Nothing -> pure Nothing
             _ -> fail "Internal error"
          cabalVer <- case runCabalVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
             Just (ToolVersion v) -> pure $ Just v
             Nothing -> pure Nothing
             _ -> fail "Internal error"
          hlsVer <- case runHLSVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
             Just (ToolVersion v) -> pure $ Just v
             Nothing -> pure Nothing
             _ -> fail "Internal error"
          stackVer <- case runStackVer of
+            Just (GHCVersion v) -> pure $ Just (_tvVersion v)
             Just (ToolVersion v) -> pure $ Just v
             Nothing -> pure Nothing
             _ -> fail "Internal error"
@@ -353,35 +352,43 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
                               , MergeFileTreeError
                               ] (ResourceT (ReaderT AppState m)) ()
    installToolChainFull Toolchain{..} tmp = do
-         forM_ [(GHC,) <$> ghcVer, (Cabal,) <$> cabalVer, (HLS,) <$> hlsVer, (Stack,) <$> stackVer] $ \mt -> do
+         case ghcVer of
-           isInstalled <- maybe (pure False) (\(tool, v) -> lift $ checkIfToolInstalled' tool v) mt
+           Just v -> do
-           case mt of
+             isInstalled <- lift $ checkIfToolInstalled' GHC v
-             Just (GHC, v) -> do
+             unless isInstalled $ when (runInstTool' && isNothing (_tvTarget v)) $ void $ liftE $ installGHCBin
-               unless isInstalled $ when (runInstTool' && isNothing (_tvTarget v)) $ void $ liftE $ installGHCBin
+               (_tvVersion v)
-                 (_tvVersion v)
+               GHCupInternal
-                 GHCupInternal
+               False
-                 False
+               []
-                 []
+             setGHC' v tmp
-               setTool GHC v tmp
+           _ -> pure ()
-             Just (Cabal, v) -> do
+         case cabalVer of
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installCabalBin
+           Just v -> do
-                 (_tvVersion v)
+             isInstalled <- lift $ checkIfToolInstalled' Cabal (mkTVer v)
-                 GHCupInternal
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installCabalBin
-                 False
+               v
-               setTool Cabal v tmp
+               GHCupInternal
-             Just (Stack, v) -> do
+               False
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installStackBin
+             setCabal' v tmp
-                 (_tvVersion v)
+           _ -> pure ()
-                 GHCupInternal
+         case stackVer of
-                 False
+           Just v -> do
-               setTool Stack v tmp
+             isInstalled <- lift $ checkIfToolInstalled' Stack (mkTVer v)
-             Just (HLS, v) -> do
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installStackBin
-               unless isInstalled $ when runInstTool' $ void $ liftE $ installHLSBin
+               v
-                 (_tvVersion v)
+               GHCupInternal
-                 GHCupInternal
+               False
-                 False
+             setStack' v tmp
-               setTool HLS v tmp
+           _ -> pure ()
-             _ -> pure ()
+         case hlsVer of
+           Just v -> do
+             isInstalled <- lift $ checkIfToolInstalled' HLS (mkTVer v)
+             unless isInstalled $ when runInstTool' $ void $ liftE $ installHLSBin
+               v
+               GHCupInternal
+               False
+             setHLS' v tmp
+           _ -> pure ()
 
    installToolChain :: ( MonadFail m
                        , MonadThrow m
@@ -392,46 +399,47 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
                     -> FilePath
                     -> Excepts '[NotInstalled] (ReaderT LeanAppState m) ()
    installToolChain Toolchain{..} tmp = do
-         forM_ [(GHC,) <$> ghcVer, (Cabal,) <$> cabalVer, (HLS,) <$> hlsVer, (Stack,) <$> stackVer] $ \mt -> do
+         case ghcVer of
-           case mt of
+           Just v -> setGHC' v tmp
-             Just (GHC, v)   -> setTool GHC v tmp
+           _ -> pure ()
-             Just (Cabal, v) -> setTool Cabal v tmp
+         case cabalVer of
-             Just (Stack, v) -> setTool Stack v tmp
+           Just v -> setCabal' v tmp
-             Just (HLS, v)   -> setTool HLS v tmp
+           _ -> pure ()
-             _ -> pure ()
+         case stackVer of
+           Just v -> setStack' v tmp
+           _ -> pure ()
+         case hlsVer of
+           Just v -> setHLS' v tmp
+           _ -> pure ()
 
-   setTool tool v tmp =
+   setGHC' v tmp = do
-      case tool of
-        GHC -> do
           void $ liftE $ setGHC v SetGHC_XYZ (Just tmp)
           void $ liftE $ setGHC v SetGHCOnly (Just tmp)
-        Cabal -> do
+   setCabal' v tmp = do
-          bin  <- liftE $ whereIsTool Cabal v
+          bin  <- liftE $ whereIsTool Cabal (mkTVer v)
           cbin <- liftIO $ canonicalizePath bin
           lift $ createLink (relativeSymlink tmp cbin) (tmp </> ("cabal" <.> exeExt))
-        Stack -> do
+   setStack' v tmp = do
-          bin  <- liftE $ whereIsTool Stack v
+          bin  <- liftE $ whereIsTool Stack (mkTVer v)
           cbin <- liftIO $ canonicalizePath bin
           lift $ createLink (relativeSymlink tmp cbin) (tmp </> ("stack" <.> exeExt))
-        HLS -> do
+   setHLS' v tmp = do
           Dirs {..}  <- getDirs
-          let v' = _tvVersion v
+          legacy <- isLegacyHLS v
-          legacy <- isLegacyHLS v'
           if legacy
           then do
             -- TODO: factor this out
-            hlsWrapper <- liftE @_ @'[NotInstalled] $ hlsWrapperBinary v' !? (NotInstalled HLS (mkTVer v'))
+            hlsWrapper <- liftE @_ @'[NotInstalled] $ hlsWrapperBinary v !? (NotInstalled HLS (mkTVer v))
             cw <- liftIO $ canonicalizePath (binDir </> hlsWrapper)
             lift $ createLink (relativeSymlink tmp cw) (tmp </> takeFileName cw)
-            hlsBins <- hlsServerBinaries v' Nothing >>= liftIO . traverse (canonicalizePath . (binDir </>))
+            hlsBins <- hlsServerBinaries v Nothing >>= liftIO . traverse (canonicalizePath . (binDir </>))
             forM_ hlsBins $ \bin ->
               lift $ createLink (relativeSymlink tmp bin) (tmp </> takeFileName bin)
-            liftE $ setHLS (_tvVersion v) SetHLSOnly (Just tmp)
+            liftE $ setHLS v SetHLSOnly (Just tmp)
           else do
-            liftE $ setHLS (_tvVersion v) SetHLS_XYZ (Just tmp)
+            liftE $ setHLS v SetHLS_XYZ (Just tmp)
-            liftE $ setHLS (_tvVersion v) SetHLSOnly (Just tmp)
+            liftE $ setHLS v SetHLSOnly (Just tmp)
-        GHCup -> pure ()
+
-       
    addToPath path = do
     cEnv <- Map.fromList <$> getEnvironment
     let paths          = ["PATH", "Path"]
@@ -443,16 +451,38 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
     liftIO $ setEnv pathVar newPath
     return envWithNewPath
 
-   predictableTmpDir (Toolchain Nothing Nothing Nothing Nothing) =
+   createTmpDir :: ( MonadUnliftIO m
-     liftIO (getTemporaryDirectory >>= \tmp -> pure (tmp </> "ghcup-none"))
+                   , MonadCatch m
+                   , MonadThrow m
+                   , MonadMask m
+                   , MonadIO m
+                   )
+                => Toolchain
+                -> ReaderT LeanAppState m FilePath
+   createTmpDir toolchain =
+     case runBinDir of
+           Just bindir -> do
+             liftIO $ createDirRecursive' bindir
+             liftIO $ canonicalizePath bindir
+           Nothing -> do
+             d <- predictableTmpDir toolchain
+             liftIO $ createDirRecursive' d
+             liftIO $ canonicalizePath d
+
+   predictableTmpDir :: Monad m
+                     => Toolchain
+                     -> ReaderT LeanAppState m FilePath
+   predictableTmpDir (Toolchain Nothing Nothing Nothing Nothing) = do
+     Dirs { tmpDir } <- getDirs
+     pure (fromGHCupPath tmpDir </> "ghcup-none")
    predictableTmpDir Toolchain{..} = do
-      tmp <- getTemporaryDirectory
+      Dirs { tmpDir } <- getDirs
-      pure $ tmp
+      pure $ fromGHCupPath tmpDir
         </> ("ghcup-" <> intercalate "_"
               (  maybe [] ( (:[]) . ("ghc-"   <>) . T.unpack . tVerToText) ghcVer
-              <> maybe [] ( (:[]) . ("cabal-" <>) . T.unpack . tVerToText) cabalVer
+              <> maybe [] ( (:[]) . ("cabal-" <>) . T.unpack . prettyVer) cabalVer
-              <> maybe [] ( (:[]) . ("hls-"   <>) . T.unpack . tVerToText) hlsVer
+              <> maybe [] ( (:[]) . ("hls-"   <>) . T.unpack . prettyVer) hlsVer
-              <> maybe [] ( (:[]) . ("stack-" <>) . T.unpack . tVerToText) stackVer
+              <> maybe [] ( (:[]) . ("stack-" <>) . T.unpack . prettyVer) stackVer
               )
             )
 
@@ -466,7 +496,7 @@ run RunOptions{..} runAppState leanAppstate runLogger = do
 
 data Toolchain = Toolchain
   { ghcVer     :: Maybe GHCTargetVersion
-  , cabalVer   :: Maybe GHCTargetVersion
+  , cabalVer   :: Maybe Version
-  , hlsVer     :: Maybe GHCTargetVersion
+  , hlsVer     :: Maybe Version
-  , stackVer   :: Maybe GHCTargetVersion
+  , stackVer   :: Maybe Version
-  }
+  } deriving Show

app/ghcup/GHCup/OptParse/Set.hs

@@ -74,7 +74,7 @@ data SetOptions = SetOptions
     --[ Parsers ]--
     ---------------
 
-          
+
 setParser :: Parser (Either SetCommand SetOptions)
 setParser =
   (Left <$> subparser
@@ -82,7 +82,7 @@ setParser =
           "ghc"
           (   SetGHC
           <$> info
-                (setOpts (Just GHC) <**> helper)
+                (setOpts GHC <**> helper)
                 (  progDesc "Set GHC version"
                 <> footerDoc (Just $ text setGHCFooter)
                 )
@@ -91,7 +91,7 @@ setParser =
            "cabal"
            (   SetCabal
            <$> info
-                 (setOpts (Just Cabal) <**> helper)
+                 (setOpts Cabal <**> helper)
                  (  progDesc "Set Cabal version"
                  <> footerDoc (Just $ text setCabalFooter)
                  )
@@ -100,7 +100,7 @@ setParser =
            "hls"
            (   SetHLS
            <$> info
-                 (setOpts (Just HLS) <**> helper)
+                 (setOpts HLS <**> helper)
                  (  progDesc "Set haskell-language-server version"
                  <> footerDoc (Just $ text setHLSFooter)
                  )
@@ -109,14 +109,14 @@ setParser =
            "stack"
            (   SetStack
            <$> info
-                 (setOpts (Just Stack) <**> helper)
+                 (setOpts Stack <**> helper)
                  (  progDesc "Set stack version"
                  <> footerDoc (Just $ text setStackFooter)
                  )
            )
       )
     )
-    <|> (Right <$> setOpts Nothing)
+    <|> (Right <$> setOpts GHC)
  where
   setGHCFooter :: String
   setGHCFooter = [s|Discussion:
@@ -137,22 +137,25 @@ setParser =
     Sets the the current haskell-language-server version.|]
 
 
-setOpts :: Maybe Tool -> Parser SetOptions
+setOpts :: Tool -> Parser SetOptions
 setOpts tool = SetOptions <$>
     (fromMaybe SetRecommended <$>
       optional (setVersionArgument (Just ListInstalled) tool))
 
-setVersionArgument :: Maybe ListCriteria -> Maybe Tool -> Parser SetToolVersion
+setVersionArgument :: Maybe ListCriteria -> Tool -> Parser SetToolVersion
 setVersionArgument criteria tool =
   argument (eitherReader setEither)
     (metavar "VERSION|TAG|next"
-    <> completer (tagCompleter (fromMaybe GHC tool) ["next"])
+    <> completer (tagCompleter tool ["next"])
-    <> foldMap (completer . versionCompleter criteria) tool)
+    <> (completer . versionCompleter criteria) tool)
  where
   setEither s' =
         parseSet s'
     <|> second SetToolTag (tagEither s')
-    <|> second SetToolVersion (tVersionEither s')
+    <|> se s'
+  se s' = case tool of
+           GHC -> second SetGHCVersion (ghcVersionEither s')
+           _   -> second SetToolVersion (toolVersionEither s')
   parseSet s' = case fmap toLower s' of
                   "next" -> Right SetNext
                   other  -> Left $ "Unknown tag/version " <> other
@@ -261,9 +264,9 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
   (Right sopts) -> do
     runLogger (logWarn "This is an old-style command for setting GHC. Use 'ghcup set ghc' instead.")
     setGHC' sopts
-  (Left (SetGHC sopts)) -> setGHC' sopts
+  (Left (SetGHC sopts))   -> setGHC'   sopts
   (Left (SetCabal sopts)) -> setCabal' sopts
-  (Left (SetHLS sopts)) -> setHLS' sopts
+  (Left (SetHLS sopts))   -> setHLS'   sopts
   (Left (SetStack sopts)) -> setStack' sopts
 
  where
@@ -271,7 +274,7 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
           -> m ExitCode
   setGHC' SetOptions{ sToolVer } =
     case sToolVer of
-      (SetToolVersion v) -> runSetGHC runLeanAppState (liftE $ setGHC v SetGHCOnly Nothing >> pure v)
+      (SetGHCVersion v) -> runSetGHC runLeanAppState (liftE $ setGHC v SetGHCOnly Nothing >> pure v)
       _ -> runSetGHC runAppState (do
           v <- liftE $ fst <$> fromVersion' sToolVer GHC
           liftE $ setGHC v SetGHCOnly Nothing
@@ -291,17 +294,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
             -> m ExitCode
   setCabal' SetOptions{ sToolVer } =
     case sToolVer of
-      (SetToolVersion v) -> runSetCabal runLeanAppState (liftE $ setCabal (_tvVersion v) >> pure v)
+      (SetToolVersion v) -> runSetCabal runLeanAppState (liftE $ setCabal v >> pure (mkTVer v))
       _ -> runSetCabal runAppState (do
           v <- liftE $ fst <$> fromVersion' sToolVer Cabal
           liftE $ setCabal (_tvVersion v)
           pure v
         )
       >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
               runLogger
                 $ logInfo $
-                    "Cabal " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "Cabal " <> prettyVer (_tvVersion v) <> " successfully set as default version"
               pure ExitSuccess
             VLeft  e -> do
               runLogger $ logError $ T.pack $ prettyShow e
@@ -311,17 +314,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
           -> m ExitCode
   setHLS' SetOptions{ sToolVer } =
     case sToolVer of
-      (SetToolVersion v) -> runSetHLS runLeanAppState (liftE $ setHLS (_tvVersion v) SetHLSOnly Nothing >> pure v)
+      (SetToolVersion v) -> runSetHLS runLeanAppState (liftE $ setHLS v SetHLSOnly Nothing >> pure (mkTVer v))
       _ -> runSetHLS runAppState (do
           v <- liftE $ fst <$> fromVersion' sToolVer HLS
           liftE $ setHLS (_tvVersion v) SetHLSOnly Nothing
           pure v
         )
       >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
               runLogger
                 $ logInfo $
-                    "HLS " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "HLS " <> prettyVer (_tvVersion v) <> " successfully set as default version"
               pure ExitSuccess
             VLeft  e -> do
               runLogger $ logError $ T.pack $ prettyShow e
@@ -332,17 +335,17 @@ set setCommand runAppState runLeanAppState runLogger = case setCommand of
             -> m ExitCode
   setStack' SetOptions{ sToolVer } =
     case sToolVer of
-      (SetToolVersion v) -> runSetStack runLeanAppState (liftE $ setStack (_tvVersion v) >> pure v)
+      (SetToolVersion v) -> runSetStack runLeanAppState (liftE $ setStack v >> pure (mkTVer v))
       _ -> runSetStack runAppState (do
             v <- liftE $ fst <$> fromVersion' sToolVer Stack
             liftE $ setStack (_tvVersion v)
             pure v
           )
       >>= \case
-            VRight GHCTargetVersion{..} -> do
+            VRight v -> do
               runLogger
                 $ logInfo $
-                    "Stack " <> prettyVer _tvVersion <> " successfully set as default version"
+                    "Stack " <> prettyVer (_tvVersion v) <> " successfully set as default version"
               pure ExitSuccess
             VLeft  e -> do
               runLogger $ logError $ T.pack $ prettyShow e

app/ghcup/GHCup/OptParse/Whereis.hs

@@ -75,14 +75,14 @@ data WhereisOptions = WhereisOptions {
     --[ Parsers ]--
     ---------------
 
-          
+
 whereisP :: Parser WhereisCommand
 whereisP = subparser
-  (commandGroup "Tools locations:" <> 
+  (commandGroup "Tools locations:" <>
     command
       "ghc"
       (WhereisTool GHC <$> info
-        ( optional (toolVersionArgument Nothing (Just GHC)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just GHC)) <**> helper )
         ( progDesc "Get GHC location"
         <> footerDoc (Just $ text whereisGHCFooter ))
       )
@@ -90,7 +90,7 @@ whereisP = subparser
      command
       "cabal"
       (WhereisTool Cabal <$> info
-        ( optional (toolVersionArgument Nothing (Just Cabal)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just Cabal)) <**> helper )
         ( progDesc "Get cabal location"
         <> footerDoc (Just $ text whereisCabalFooter ))
       )
@@ -98,7 +98,7 @@ whereisP = subparser
      command
       "hls"
       (WhereisTool HLS <$> info
-        ( optional (toolVersionArgument Nothing (Just HLS)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just HLS)) <**> helper )
         ( progDesc "Get HLS location"
         <> footerDoc (Just $ text whereisHLSFooter ))
       )
@@ -106,7 +106,7 @@ whereisP = subparser
      command
       "stack"
       (WhereisTool Stack <$> info
-        ( optional (toolVersionArgument Nothing (Just Stack)) <**> helper )
+        ( optional (toolVersionTagArgument Nothing (Just Stack)) <**> helper )
         ( progDesc "Get stack location"
         <> footerDoc (Just $ text whereisStackFooter ))
       )
@@ -268,7 +268,7 @@ whereis :: ( Monad m
 whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
   Dirs{ .. }  <- runReaderT getDirs leanAppstate
   case (whereisCommand, whereisOptions) of
-    (WhereisTool tool (Just (ToolVersion v)), WhereisOptions{..}) ->
+    (WhereisTool tool (Just (GHCVersion v)), WhereisOptions{..}) ->
       runLeanWhereIs leanAppstate (do
         loc <- liftE $ whereIsTool tool v
         if directory
@@ -282,6 +282,20 @@ whereis whereisCommand whereisOptions runAppState leanAppstate runLogger = do
               VLeft e -> do
                 runLogger $ logError $ T.pack $ prettyShow e
                 pure $ ExitFailure 30
+    (WhereisTool tool (Just (ToolVersion v)), WhereisOptions{..}) ->
+      runLeanWhereIs leanAppstate (do
+        loc <- liftE $ whereIsTool tool (mkTVer v)
+        if directory
+        then pure $ takeDirectory loc
+        else pure loc
+        )
+        >>= \case
+              VRight r -> do
+                liftIO $ putStr r
+                pure ExitSuccess
+              VLeft e -> do
+                runLogger $ logError $ T.pack $ prettyShow e
+                pure $ ExitFailure 30
 
     (WhereisTool tool whereVer, WhereisOptions{..}) -> do
       runWhereIs runAppState (do

app/ghcup/Main.hs

@@ -238,7 +238,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                     | Just False <- optVerbose -> pure ()
                     | otherwise -> lookupEnv "GHCUP_SKIP_UPDATE_CHECK" >>= \case
                          Nothing -> void . flip runReaderT s' . runE @'[TagNotFound, NextVerNotFound, NoToolVersionSet] $ do
-                           newTools <- lift checkForUpdates 
+                           newTools <- lift checkForUpdates
                            forM_ newTools $ \newTool@(t, l) -> do
                              -- https://gitlab.haskell.org/haskell/ghcup-hs/-/issues/283
                              alreadyInstalling' <- alreadyInstalling optCommand newTool
@@ -279,7 +279,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
               runAppState action' = do
                 s' <- liftIO appState
                 runReaderT action' s'
-                  
+
 
           -----------------
           -- Run command --
@@ -339,16 +339,16 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
   alreadyInstalling (Install (Left (InstallHLS InstallOptions{..})))     (HLS, ver)   = cmp' HLS instVer ver
   alreadyInstalling (Install (Left (InstallStack InstallOptions{..})))   (Stack, ver) = cmp' Stack instVer ver
   alreadyInstalling (Compile (CompileGHC GHCCompileOptions{ ovewrwiteVer = Just over }))
-    (GHC, ver)   = cmp' GHC (Just $ ToolVersion (mkTVer over)) ver
+    (GHC, ver)   = cmp' GHC (Just $ GHCVersion (mkTVer over)) ver
   alreadyInstalling (Compile (CompileGHC GHCCompileOptions{ targetGhc = GHC.SourceDist tver }))
-    (GHC, ver)   = cmp' GHC (Just $ ToolVersion (mkTVer tver)) ver
+    (GHC, ver)   = cmp' GHC (Just $ ToolVersion tver) ver
   alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ ovewrwiteVer = Right over }))
-    (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer over)) ver
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion over) ver
   alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = HLS.SourceDist tver }))
-    (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer tver)) ver
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion tver) ver
   alreadyInstalling (Compile (CompileHLS HLSCompileOptions{ targetHLS = HLS.HackageDist tver }))
-    (HLS, ver)   = cmp' HLS (Just $ ToolVersion (mkTVer tver)) ver
+    (HLS, ver)   = cmp' HLS (Just $ ToolVersion tver) ver
-  alreadyInstalling (Upgrade _ _ _) (GHCup, _) = pure True
+  alreadyInstalling (Upgrade {}) (GHCup, _) = pure True
   alreadyInstalling _ _ = pure False
 
   cmp' :: ( HasLog env

docs/guide.md

@@ -4,7 +4,7 @@ This is a more in-depth guide specific to GHCup. `ghcup --help` is your friend.
 
 ## Basic usage
 
-For the simple interactive TUI (not available on windows), run:
+For the simple, interactive, text-based user interface (TUI) (not available on windows), run:
 
 ```sh
 ghcup tui
@@ -186,6 +186,51 @@ url-source:
 
 # More on installation
 
+## Customisation of the installation scripts
+
+The scripts offered to install GHCup are available here:
+
+* [bootstrap-haskell](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell#L7)
+  for Unix-like operating systems
+* [bootstrap-haskell.ps1](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell.ps1#L17)
+  for Windows (PowerShell). This will, in turn, run the final bootstrap script
+  (by default, that for the Unix-like operating systems).
+
+The effect of the scripts can be customised by setting one or more
+`BOOTSTRAP_HASKELL_*` environment variables (as set out in the first script)
+and, in the case of Windows, by specifying parameters (as set out in the
+PowerShell script).
+
+For example, you can toggle:
+
+* non-interactive installation
+* a more verbose installation
+* whether to install only GHCup (and, on Windows, MSYS2)
+* not to trigger the upgrade of GHCup
+* whether to install the latest version of HLS
+* whether to install the latest version of Stack
+* whether to respect the XDG Base Directory Specification
+* whether to adjust (prepend) the PATH in `bashrc`
+* on Windows, whether to adjust MINGW paths in `cabal.config`
+
+You can also specify:
+
+* the GHC version to install
+* the Cabal version to install
+* which downloader to use (the default is `curl`)
+* the base URL for the download of the GHCup binary distribution
+
+On Windows, you can also use the parameters to:
+
+* toggle whether to overwrite a previous installation
+* specify the GHCup installation root directory
+* specify the Cabal root directory
+* specify the directory of an existing installation of MSYS2 (for example,
+  the one supplied by Stack)
+* specify the URL of the final bootstrap script
+* toggle whether to run the final bootstrap script via `bash` (instead of in a
+  new MSYS2 shell)
+
 ## Installing custom bindists
 
 There are a couple of good use cases to install custom bindists:
@@ -193,7 +238,8 @@ There are a couple of good use cases to install custom bindists:
 1. manually built bindists (e.g. with patches)
     - example: `ghcup install ghc -u 'file:///home/mearwald/tmp/ghc-eff-patches/ghc-8.10.2-x86_64-deb10-linux.tar.xz' 8.10.2-eff`
 2. GHC head CI bindists
-    - example: `ghcup install ghc -u 'https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27' head`
+    - example specifying a branch (`master`): `ghcup install ghc -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head`
+    - example specifying a job id (`1129565`): `ghcup install ghc -u ' https://gitlab.haskell.org/api/v4/projects/1/jobs/1129565/artifacts/ghc-x86_64-linux-alpine3_12-validate+fully_static.tar.xz' mr7847`
 3. DWARF bindists
     - example: `ghcup install ghc -u 'https://downloads.haskell.org/~ghc/8.10.2/ghc-8.10.2-x86_64-deb10-linux-dwarf.tar.xz' 8.10.2-dwarf`
 
@@ -257,6 +303,23 @@ To instruct cabal to run `cabal update` before building, run `ghcup compile hls
 
 As always, check `ghcup compile hls --help`.
 
+#### Updating HLS for a new GHC version
+
+First try to build from hackage with some tricks:
+
+```sh
+ghcup compile hls --version 1.7.0.0 --ghc 9.2.4 --cabal-update -- --allow-newer --index-state=2022-06-12T00:00:00Z
+```
+
+This augments the currently installed 1.7.0.0 official bindists in ghcup with new GHC versions support.
+
+If that fails (since `--allow-newer` is quite brutal), you can install from HLS master branch (which may contain new fixes) like so:
+```
+ghcup compile hls --git-ref master --git-describe-version --ghc 8.10.7 --ghc 9.2.4 --cabal-update
+```
+
+This however will create a new HLS version in ghcup, e.g. `1.7.0.0-105-gdc682ba1`, for both 8.10.7 and 9.2.4. If you want to switch back to the official bindists, run `ghcup set hls 1.7.0.0`.
+
 ### Cross support
 
 ghcup can compile and install a cross GHC for any target. However, this
@@ -284,24 +347,26 @@ You need to use the `--isolate` or `-i` flag followed by the directory path.
 
 Examples:
 
-1. install an isolated GHC version at location /home/user/isolated_dir/ghc/  
+1. install an isolated GHC version at location /home/user/isolated_dir/ghc/
     - `ghcup install ghc 8.10.5 --isolate /home/user/isolated_dir/ghc`
 
-2. isolated install Cabal at a location you desire  
+2. isolated install Cabal at a location you desire
     - `ghcup install cabal --isolate /home/username/my_isolated_dir/`
 
-3. do an isolated install with a custom bindist  
+3. do an isolated install with a custom bindist
-    - `ghcup install ghc --isolate /home/username/my_isolated_dir/ -u 'https://gitlab.haskell.org/api/v4/projects/1/jobs/artifacts/master/raw/ghc-x86_64-fedora27-linux.tar.xz?job=validate-x86_64-linux-fedora27' head`
+    - `ghcup install ghc --isolate /home/username/my_isolated_dir/ -u 'https://gitlab.haskell.org/ghc/ghc/-/jobs/artifacts/master/raw/ghc-x86_64-linux-fedora33-release.tar.xz?job=x86_64-linux-fedora33-release' head`
 
-4. isolated install HLS  
+4. isolated install HLS
     - `ghcup install hls --isolate /home/username/dir/hls/`
 
-5. you can even compile ghc to an isolated location.  
+5. you can even compile ghc to an isolated location.
-    - `ghcup compile ghc -j 4 -v 9.0.1 -b 8.10.5 -i /home/username/my/dir/ghc` 
+    - `ghcup compile ghc -j 4 -v 9.0.1 -b 8.10.5 -i /home/username/my/dir/ghc`
 
 ## Continuous integration
 
-On windows, ghcup can be installed automatically on a CI runner non-interactively like so:
+On Windows, GHCup can be installed automatically on a CI runner
+non-interactively, as below. The paramaters to the PowerShell script are
+specified positionally, after `-ArgumentList`:
 
 ```ps
 Set-ExecutionPolicy Bypass -Scope Process -Force;[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072;Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Invoke-WebRequest https://www.haskell.org/ghcup/sh/bootstrap-haskell.ps1 -UseBasicParsing))) -ArgumentList $false,$true,$true,$false,$false,$false,$false,"C:\"
@@ -313,12 +378,10 @@ On linux/darwin/freebsd, run the following on your runner:
 curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | BOOTSTRAP_HASKELL_NONINTERACTIVE=1 BOOTSTRAP_HASKELL_MINIMAL=1 sh
 ```
 
-This will just install `ghcup` and on windows additionally `msys2`.
+This will just install `ghcup` and on Windows additionally MSYS2.
 
-For the full list of env variables and parameters to tweak the script behavior, see:
+See the installation scripts referred to above for the full list of environment
-
+variables and, in the case of Windows, parameters to tweak the script behavior.
-* [bootstrap-haskell for linux/darwin/freebsd](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell#L7)
-* [bootstrap-haskell.ps1 for windows](https://gitlab.haskell.org/haskell/ghcup-hs/-/blob/master/scripts/bootstrap/bootstrap-haskell.ps1#L17)
 
 ### github workflows
 
@@ -353,7 +416,7 @@ gpg-setting: GPGLax # GPGStrict | GPGLax | GPGNone
 
 In `GPGStrict` mode, ghcup will fail if verification fails. In `GPGLax` mode it will just print a warning.
 You can also pass the mode via `ghcup --gpg <strict|lax|none>`.
-   
+
 # Tips and tricks
 
 ## ghcup run
@@ -367,3 +430,34 @@ ghcup run --ghc 8.10.7 --cabal latest --hls latest --stack latest --install -- c
 ```
 
 This will execute vscode with GHC set to 8.10.7 and all other tools to their latest version.
+
+# Troubleshooting
+
+## Script immediately exits on windows
+
+There are two possible reasons:
+
+1. your company blocks the script (some have a whitelist)... ask your administrator
+2. your Antivirus or Windows Defender interfere with the installation. Disable them temporarily.
+
+## C compiler cannot create executables
+
+### Darwin
+
+You need to update your XCode command line tools, e.g. [like this](https://stackoverflow.com/questions/34617452/how-to-update-xcode-from-command-line).
+
+## Certificate authority errors (curl)
+
+If your certificates are outdated or improperly configured, curl may be unable
+to download ghcup.
+
+There are two known workarounds:
+
+1. Tell curl to ignore certificate errors (dangerous): `curl -k https://gitlab.haskell.org/haskell/ghcup-hs/-/raw/master/scripts/bootstrap/bootstrap-haskell | GHCUP_CURL_OPTS="-k" sh`
+2. Try to use wget instead: `wget -O /dev/stdout https://gitlab.haskell.org/haskell/ghcup-hs/-/raw/master/scripts/bootstrap/bootstrap-haskell | BOOTSTRAP_HASKELL_DOWNLOADER=wget sh`
+
+On windows, you can disable curl like so:
+
+```pwsh
+Set-ExecutionPolicy Bypass -Scope Process -Force;[System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072;Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Invoke-WebRequest https://www.haskell.org/ghcup/sh/bootstrap-haskell.ps1 -UseBasicParsing))) -ArgumentList $true,$false,$false,$false,$false,$false,$false,"","","","",$true
+```

docs/index.md

@@ -57,7 +57,7 @@ hide:
 </section>
 
 <p id="help" class="ghcup-help">
-  Need help? Ask on
+  Need help? Check the <a href="guide/#troubleshooting">Troubleshooting section</a> or ask on
   <span>
     <a href="https://kiwiirc.com/nextclient/irc.libera.chat/?nick=Guest%7C?#haskell,#haskell-ghcup">
       <img src="irc.svg" alt="" />

docs/install.md

@@ -55,7 +55,9 @@ GHCup supports the following tools, which are also known as the **Haskell Toolch
 <table>
 <thead><tr><th>GHC Version</th><th>Tags</th></tr></thead>
 <tbody>
-<tr><td>9.2.3</td><td><span style="color:blue">latest</span>, base-4.16.2.0</td></tr>
+<tr><td>9.4.1</td><td><span style="color:blue">latest</span>, base-4.17.0.0</td></tr>
+<tr><td>9.2.4</td><td>base-4.16.3.0</td></tr>
+<tr><td>9.2.3</td><td>base-4.16.2.0</td></tr>
 <tr><td>9.2.2</td><td>base-4.16.1.0</td></tr>
 <tr><td>9.2.1</td><td>base-4.16.0.0</td></tr>
 <tr><td>9.0.2</td><td>base-4.15.1.0</td></tr>
@@ -208,6 +210,8 @@ The developers of the Haskell Language Server offer an [extension](https://githu
 3. Make sure your project uses the GHC version installed from GHCup (otherwise HLS is likely to fail on launch):
     - instructions for [stack](https://docs.haskellstack.org/en/stable/yaml_configuration/#system-ghc)
 
+On Linux, some users have reported an issue when VSCode is not launched from a terminal ("cannot find ghc version"). A solution is to [let HLS know about your GHCup on $PATH](https://github.com/haskell/vscode-haskell#stackcabalghc-can-not-be-found).
+
 ## Get help
 
 * [Libera IRC chat on #haskell-ghcup or #haskell](https://kiwiirc.com/nextclient/irc.libera.chat/?nick=Guest%7C?#haskell,#haskell-ghcup)

docs/steps.md

@@ -335,7 +335,7 @@ see the [Cabal user guide](https://cabal.readthedocs.io/en/stable/getting-starte
 
 To learn Haskell, try any of those:
 
-- A beginner friendly [4-lectures course](https://github.com/haskell-beginners-2022/course-plan) with exercises (by [Kowainik](https://kowainik.github.io/))
+- A beginner friendly [4-lectures course](https://github.com/haskell-beginners-2022/course-plan) with exercises (by [Dmitrii Kovanikov](https://kodimensional.dev/))
 - An in-depth university [CIS 194 Haskell course](https://www.cis.upenn.edu/~cis194/spring13/) including exercises (by [Brent Yorgey](https://byorgey.wordpress.com/))
 
 ## Projects to contribute to

ghcup.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ghcup
-version:            0.1.18.0
+version:            0.1.18.1
 license:            LGPL-3.0-only
 license-file:       LICENSE
 copyright:          Julian Ospald 2020
@@ -21,6 +21,8 @@ extra-doc-files:
   README.md
 
 extra-source-files:
+  cbits/dirutils.c
+  cbits/dirutils.h
   data/build_mk/cross
   data/build_mk/default
   test/golden/GHCupInfo.json
@@ -69,6 +71,7 @@ library
     GHCup.Prelude.Process
     GHCup.Prelude.String.QQ
     GHCup.Prelude.Version.QQ
+    GHCup.Prompts
     GHCup.Requirements
     GHCup.Stack
     GHCup.Types
@@ -161,14 +164,13 @@ library
       , terminal-progress-bar  >=0.4.1
 
   if os(windows)
-    cpp-options:   -DIS_WINDOWS
+    cpp-options:     -DIS_WINDOWS
     other-modules:
       GHCup.Prelude.File.Windows
       GHCup.Prelude.Windows
-    -- GHCup.OptParse.Run uses this
-    exposed-modules:
-      GHCup.Prelude.Process.Windows
 
+    -- GHCup.OptParse.Run uses this
+    exposed-modules: GHCup.Prelude.Process.Windows
     build-depends:
       , bzlib
       , process  ^>=1.6.11.0
@@ -182,7 +184,10 @@ library
       GHCup.Prelude.Posix
       GHCup.Prelude.Process.Posix
 
-    c-sources:     cbits/dirutils.c
+    include-dirs:     cbits
+    includes:         dirutils.h
+    install-includes: dirutils.h
+    c-sources:        cbits/dirutils.c
     build-depends:
       , bz2              >=0.5.0.5 && <1.1
       , terminal-size    ^>=0.3.2.1
@@ -236,7 +241,7 @@ executable ghcup
     , aeson-pretty          ^>=0.8.8
     , async                 ^>=2.2.3
     , base                  >=4.12     && <5
-    , bytestring            >=0.10       && <0.12
+    , bytestring            >=0.10     && <0.12
     , cabal-plan            ^>=0.7.2
     , containers            ^>=0.6
     , deepseq               ^>=1.4
@@ -313,11 +318,11 @@ test-suite ghcup-test
 
   build-depends:
     , base                      >=4.12    && <5
-    , bytestring            >=0.10       && <0.12
+    , bytestring                >=0.10    && <0.12
     , containers                ^>=0.6
     , directory                 ^>=1.3.6.0
     , filepath                  ^>=1.4.2.1
-    , generic-arbitrary         >=0.1.0  && < 0.2.1 || >=0.2.2 && <0.3
+    , generic-arbitrary         >=0.1.0   && <0.2.1 || >=0.2.2 && <0.3
     , ghcup
     , hspec                     >=2.7.10  && <2.10
     , hspec-golden-aeson        ^>=0.9

lib/GHCup/Errors.hs

@@ -137,8 +137,8 @@ data AlreadyInstalled = AlreadyInstalled Tool Version
 
 instance Pretty AlreadyInstalled where
   pPrint (AlreadyInstalled tool ver') =
-    pPrint tool <+> text "-" <+> pPrint ver' <+> text "is already installed;"
+    (pPrint tool <> text "-" <> pPrint ver') <+> text "is already installed;"
-    <+> text "if you really want to reinstall it, you may want to run 'ghcup install cabal --force" <+> (pPrint ver' <> text "'")
+    <+> text "if you really want to reinstall it, you may want to run 'ghcup install" <+> pPrint tool <+> text "--force" <+> (pPrint ver' <> text "'")
 
 
 -- | The Directory is supposed to be empty, but wasn't.

lib/GHCup/GHC.hs

@@ -301,8 +301,9 @@ installUnpackedGHC path inst ver forceInstall addConfArgs
   | otherwise = do
       PlatformRequest {..} <- lift getPlatformReq
 
-      let alpineArgs
+      let ldOverride
-           | ver >= [vver|8.2.2|], Linux Alpine <- _rPlatform
+           | ver >= [vver|8.2.2|]
+           , _rPlatform `elem` [Linux Alpine, Darwin]
            = ["--disable-ld-override"]
            | otherwise
            = []
@@ -310,7 +311,7 @@ installUnpackedGHC path inst ver forceInstall addConfArgs
       lift $ logInfo "Installing GHC (this may take a while)"
       lEM $ execLogged "sh"
                        ("./configure" : ("--prefix=" <> fromInstallDir inst)
-                        : (alpineArgs <> (T.unpack <$> addConfArgs))
+                        : (ldOverride <> (T.unpack <$> addConfArgs))
                        )
                        (Just $ fromGHCupPath path)
                        "ghc-configure"

lib/GHCup/Prompts.hs

@@ -0,0 +1,28 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE FlexibleContexts #-}
+
+module GHCup.Prompts
+  ( PromptQuestion,
+    PromptResponse (..),
+    getUserPromptResponse,
+  )
+where
+
+import Control.Monad.Reader
+import qualified Data.Text.IO as TIO
+import GHCup.Prelude.Logger
+import GHCup.Types.Optics
+import GHCup.Types (PromptQuestion, PromptResponse(..))
+
+getUserPromptResponse :: ( HasLog env
+                         , MonadReader env m
+                         , MonadIO m)
+                      => PromptQuestion
+                      -> m PromptResponse
+
+getUserPromptResponse prompt = do
+  logInfo prompt
+  resp <- liftIO TIO.getLine
+  if resp `elem` ["YES", "yes", "y", "Y"]
+    then pure PromptYes
+    else pure PromptNo

lib/GHCup/Types.hs

@@ -407,6 +407,9 @@ data AppState = AppState
 
 instance NFData AppState
 
+fromAppState :: AppState -> LeanAppState
+fromAppState AppState {..} = LeanAppState {..}
+
 data LeanAppState = LeanAppState
   { settings :: Settings
   , dirs :: Dirs
@@ -654,3 +657,7 @@ isSafeDir (IsolateDirResolved _) = False
 isSafeDir (GHCupDir _)           = True
 isSafeDir (GHCupBinDir _)        = False
 
+type PromptQuestion = Text
+
+data PromptResponse = PromptYes | PromptNo
+  deriving (Show, Eq)

scripts/bootstrap/bootstrap-haskell

@@ -12,10 +12,12 @@
 #   * BOOTSTRAP_HASKELL_VERBOSE - any nonzero value for more verbose installation
 #   * BOOTSTRAP_HASKELL_GHC_VERSION - the ghc version to install
 #   * BOOTSTRAP_HASKELL_CABAL_VERSION - the cabal version to install
-#   * BOOTSTRAP_HASKELL_INSTALL_STACK - whether to install latest stack
+#   * BOOTSTRAP_HASKELL_INSTALL_NO_STACK - disable installation of stack
+#   * BOOTSTRAP_HASKELL_INSTALL_NO_STACK_HOOK - disable installation stack ghcup hook
 #   * BOOTSTRAP_HASKELL_INSTALL_HLS - whether to install latest hls
 #   * BOOTSTRAP_HASKELL_ADJUST_BASHRC - whether to adjust PATH in bashrc (prepend)
 #   * BOOTSTRAP_HASKELL_ADJUST_CABAL_CONFIG - whether to adjust mingw paths in cabal.config on windows
+#   * BOOTSTRAP_HASKELL_DOWNLOADER - which downloader to use (default: curl)
 #   * GHCUP_BASE_URL - the base url for ghcup binary download (use this to overwrite https://downloads.haskell.org/~ghcup with a mirror)
 
 # License: LGPL-3.0
@@ -26,10 +28,11 @@
 
 plat="$(uname -s)"
 arch=$(uname -m)
-ghver="0.1.17.8"
+ghver="0.1.18.0"
 : "${GHCUP_BASE_URL:=https://downloads.haskell.org/~ghcup}"
 
 export GHCUP_SKIP_UPDATE_CHECK=yes
+: "${BOOTSTRAP_HASKELL_DOWNLOADER:=curl}"
 
 case "${plat}" in
         MSYS*|MINGW*)
@@ -138,8 +141,12 @@ ecabal() {
 }
 
 _ecabal() {
-    # shellcheck disable=SC2086
+    if [ -n "${CABAL_BIN}" ] ; then
-    "${GHCUP_BIN}/cabal" "$@"
+        "${CABAL_BIN}" "$@"
+    else
+        # shellcheck disable=SC2086
+        "${GHCUP_BIN}/cabal" "$@"
+    fi
 }
 
 _done() {
@@ -322,11 +329,35 @@ download_ghcup() {
     esac
     case "${plat}" in
         MSYS*|MINGW*)
-			edo curl -Lf "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+	                # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+                    ;;
+                "wget")
+	                # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup.exe
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
 			edo chmod +x "${GHCUP_BIN}"/ghcup.exe
 			;;
 		*)
-			edo curl -Lf "${_url}" > "${GHCUP_BIN}"/ghcup
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+	                # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup
+                    ;;
+                "wget")
+	                # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${_url}" > "${GHCUP_BIN}"/ghcup
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
 			edo chmod +x "${GHCUP_BIN}"/ghcup
 			;;
 	esac
@@ -353,6 +384,17 @@ download_ghcup() {
 
 	# shellcheck disable=SC1090
     edo . "${GHCUP_DIR}"/env
+    case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+        "curl")
+            eghcup config set downloader Curl
+            ;;
+        "wget")
+            eghcup config set downloader Wget
+            ;;
+        *)
+            die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+            ;;
+    esac
     eghcup upgrade
 }
 
@@ -618,7 +660,7 @@ ask_hls() {
 		warn "Do you want to install haskell-language-server (HLS)?"
 		warn "HLS is a language-server that provides IDE-like functionality"
 		warn "and can integrate with different editors, such as Vim, Emacs, VS Code, Atom, ..."
-		warn "Also see https://github.com/haskell/haskell-language-server/blob/master/README.md"
+		warn "Also see https://haskell-language-server.readthedocs.io/en/stable/"
 		warn ""
 		warn "[Y] Yes  [N] No  [?] Help (default is \"N\")."
 		warn ""
@@ -651,40 +693,44 @@ ask_hls() {
 }
 
 ask_stack() {
-	if [ -n "${BOOTSTRAP_HASKELL_INSTALL_STACK}" ] ; then
+    if [ -n "${BOOTSTRAP_HASKELL_INSTALL_NO_STACK}" ] ; then
+		return 0
+    elif [ -n "${BOOTSTRAP_HASKELL_INSTALL_NO_STACK_HOOK}" ] ; then
 		return 1
 	fi
 
 	if [ -z "${BOOTSTRAP_HASKELL_NONINTERACTIVE}" ] ; then
 		echo "-------------------------------------------------------------------------------"
 
-		warn "Do you want to install stack?"
+		warn "Do you want to enable better integration of stack with GHCup?"
-		warn "Stack is a haskell build tool similar to cabal that is used by some projects."
+        warn "This means that stack won't install its own GHC versions, but uses GHCup's."
-		warn "Also see https://docs.haskellstack.org/"
+        warn "For more information see:"
+        warn "  https://docs.haskellstack.org/en/stable/yaml_configuration/#ghc-installation-customisation-experimental"
+        warn "If you want to keep stacks vanilla behavior, answer 'No'."
 		warn ""
-		warn "[Y] Yes  [N] No  [?] Help (default is \"N\")."
+		warn "[Y] Yes  [N] No  [?] Help (default is \"Y\")."
 		warn ""
 
 		while true; do
 			read -r stack_answer </dev/tty
 
 			case $stack_answer in
-				[Yy]*)
+				[Yy]* | "")
+					return 2 ;;
+				[Nn]*)
 					return 1 ;;
-				[Nn]* | "")
-					return 0 ;;
 				*)
 					echo "Possible choices are:"
 					echo
-					echo "Y - Yes, install stack"
+                    echo "Y - Yes, enable better integration (default)"
-					echo "N - No, don't install anything more (default)"
+					echo "N - No, keep stacks vanilla behavior"
 					echo
 					echo "Please make your choice and press ENTER."
 					;;
 			esac
 		done
 	else
-		return 0
+		return 2
 	fi
 
 	unset stack_answer
@@ -701,7 +747,7 @@ echo "This script can download and install the following binaries:"
 echo "  * ghcup - The Haskell toolchain installer"
 echo "  * ghc   - The Glasgow Haskell Compiler"
 echo "  * cabal - The Cabal build tool for managing Haskell software"
-echo "  * stack - (optional) A cross-platform program for developing Haskell projects"
+echo "  * stack - A cross-platform program for developing Haskell projects (similar to cabal)"
 echo "  * hls   - (optional) A language server for developers to integrate with their editor/IDE"
 echo
 if [ -z "${GHCUP_USE_XDG_DIRS}" ] ; then
@@ -780,7 +826,7 @@ else # don't install ghc and cabal
 				# we'll remove it afterwards
 				tmp_dir="$(mktemp -d)"
 				eghcup --cache install cabal -i "${tmp_dir}" "${BOOTSTRAP_HASKELL_CABAL_VERSION}"
-				PATH="${tmp_dir}:$PATH" do_cabal_config_init $ask_cabal_config_init_answer
+				CABAL_BIN="${tmp_dir}/cabal" do_cabal_config_init $ask_cabal_config_init_answer
 				rm "${tmp_dir}/cabal"
 				unset tmp_dir
 				;;
@@ -798,7 +844,35 @@ esac
 
 case $ask_stack_answer in
 	1)
-		_eghcup --cache install stack || warn "Stack installation failed, continuing anyway"
+		_eghcup --cache install stack || die "Stack installation failed"
+		;;
+	2)
+		_eghcup --cache install stack || die "Stack installation failed"
+        edo mkdir -p "${STACK_ROOOT:-$HOME/.stack}"/hooks
+        hook_exe="${STACK_ROOOT:-$HOME/.stack}"/hooks/ghc-install.sh
+        hook_url="https://www.haskell.org/ghcup/sh/hooks/stack/ghc-install.sh"
+
+        if [ -e "${hook_exe}" ] ; then
+            warn "$hook_exe already exists, skipping hook installation."
+            warn "If you want to reinstall the hook, delete it manually and re-run"
+            warn "this script!"
+        else
+            case "${BOOTSTRAP_HASKELL_DOWNLOADER}" in
+                "curl")
+                    # shellcheck disable=SC2086
+                    edo curl -Lf ${GHCUP_CURL_OPTS} "${hook_url}" > "${hook_exe}"
+                    ;;
+                "wget")
+                    # shellcheck disable=SC2086
+                    edo wget -O /dev/stdout ${GHCUP_WGET_OPTS} "${hook_url}" > "${hook_exe}"
+                    ;;
+                *)
+                    die "Unknown downloader: ${BOOTSTRAP_HASKELL_DOWNLOADER}"
+                    ;;
+            esac
+            edo chmod +x "${hook_exe}"
+        fi
+
 		;;
 	*) ;;
 esac

scripts/bootstrap/bootstrap-haskell.ps1

@@ -36,7 +36,9 @@ param (
     # Instead of installing a new MSys2, use an existing installation
     [string]$ExistingMsys2Dir,
     # Specify the cabal root directory (default: '$InstallDir\cabal')
-    [string]$CabalDir
+    [string]$CabalDir,
+    # Whether to disable use of curl.exe
+    [switch]$DisableCurl
 )
 
 $Silent = !$Interactive
@@ -425,7 +427,7 @@ if (!(Test-Path -Path ('{0}' -f $MsysDir))) {
     $archive = 'msys2-x86_64-latest.sfx.exe'
     $archivePath = ('{0}\{1}' -f ([IO.Path]::GetTempPath()), "$archive")
     
-    if (Get-Command -Name 'curl.exe' -ErrorAction SilentlyContinue) {
+    if ((Get-Command -Name 'curl.exe' -ErrorAction SilentlyContinue) -and !($DisableCurl)) {
       Exec "curl.exe" '-o' "$archivePath" ('https://repo.msys2.org/distrib/{0}' -f "$archive")
     } else {
       Get-FileWCSynchronous -url ('https://repo.msys2.org/distrib/{0}' -f $archive) -destinationFolder ([IO.Path]::GetTempPath()) -includeStats
@@ -575,8 +577,8 @@ $Msys2Shell = ('{0}\msys2_shell.cmd' -f $MsysDir)
 # The bootstrap script is always silent, since we ask relevant questions here
 $SilentExport = 'export BOOTSTRAP_HASKELL_NONINTERACTIVE=1 ;'
 
-if ($InstallStack) {
+if (!($InstallStack)) {
-  $StackInstallExport = 'export BOOTSTRAP_HASKELL_INSTALL_STACK=1 ;'
+  $StackInstallExport = 'export BOOTSTRAP_HASKELL_INSTALL_NO_STACK=1 ;'
 }
 
 if ($InstallHLS) {
@@ -591,10 +593,17 @@ if ($Minimal) {
   $MinimalExport = 'export BOOTSTRAP_HASKELL_MINIMAL=1 ;'
 }
 
-if ((Get-Process -ID $PID).ProcessName.StartsWith("bootstrap-haskell") -Or $InBash) {
+if ($DisableCurl) {
-  Exec "$Bash" '-lc' ('{4} {6} {7} {8} {9} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; [[ ''{0}'' = https* ]]  && curl --proto ''=https'' --tlsv1.2 -sSf {0} | bash || cat $(cygpath -m ''{0}'') | bash' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport)
+  $BootstrapDownloader = 'export BOOTSTRAP_HASKELL_DOWNLOADER=wget ;'
+  $DownloadScript = 'wget -O /dev/stdout'
 } else {
-  Exec "$Msys2Shell" '-mingw64' '-mintty' '-c' ('{4} {6} {7} {8} {9} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; trap ''echo Press any key to exit && read -n 1 && exit'' 2 ; [[ ''{0}'' = https* ]]  && curl --proto ''=https'' --tlsv1.2 -sSf {0} | bash || cat $(cygpath -m ''{0}'') | bash ; echo ''Press any key to exit'' && read -n 1' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport)
+  $DownloadScript = 'curl --proto ''=https'' --tlsv1.2 -sSf'
+}
+
+if ((Get-Process -ID $PID).ProcessName.StartsWith("bootstrap-haskell") -Or $InBash) {
+  Exec "$Bash" '-lc' ('{4} {6} {7} {8} {9} {10} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; [[ ''{0}'' = https* ]]  && {11} {0} | bash || cat $(cygpath -m ''{0}'') | bash' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport, $BootstrapDownloader, $DownloadScript)
+} else {
+  Exec "$Msys2Shell" '-mingw64' '-mintty' '-c' ('{4} {6} {7} {8} {9} {10} [ -n ''{1}'' ] && export GHCUP_MSYS2=$(cygpath -m ''{1}'') ; [ -n ''{2}'' ] && export GHCUP_INSTALL_BASE_PREFIX=$(cygpath -m ''{2}/'') ; export PATH=$(cygpath -u ''{3}/bin''):$PATH ; export CABAL_DIR=''{5}'' ; trap ''echo Press any key to exit && read -n 1 && exit'' 2 ; [[ ''{0}'' = https* ]]  && {11} {0} | bash || cat $(cygpath -m ''{0}'') | bash ; echo ''Press any key to exit'' && read -n 1' -f $BootstrapUrl, $MsysDir, $GhcupBasePrefix, $GhcupDir, $SilentExport, $CabalDirFull, $StackInstallExport, $HLSInstallExport, $AdjustCabalConfigExport, $MinimalExport, $BootstrapDownloader, $DownloadScript)
 }
 
 

scripts/hooks/stack/ghc-install.sh

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