Fix CI

.gitlab-ci.yml

@@ -57,7 +57,7 @@ variables:
   script:
     - ./.gitlab/script/ghcup_version.sh
   variables:
-    JSON_VERSION: "0.0.1"
+    JSON_VERSION: "0.0.2"
 
 .test_ghcup_version:linux:
   extends:
@@ -161,7 +161,7 @@ release:linux:32bit:
   before_script:
     - ./.gitlab/before_script/linux/alpine/install_deps.sh
   variables:
-    ARTIFACT: "x86_64-linux-ghcup"
+    ARTIFACT: "i386-linux-ghcup"
     GHC_VERSION: "8.8.3"
     CABAL_VERSION: "3.2.0.0"
 

.gitlab/before_script/linux/alpine/install_deps.sh

@@ -42,7 +42,8 @@ chmod +x "${GHCUP_INSTALL_BASE_PREFIX}/.ghcup/bin/cabal"
 
 # utils
 apk add --no-cache \
-	bash
+	bash \
+	git
 
 ## Package specific
 apk add --no-cache \

.gitlab/before_script/linux/install_deps.sh

@@ -3,7 +3,7 @@
 set -eux
 
 sudo apt-get update -y
-sudo apt-get install -y libnuma-dev zlib1g-dev libgmp-dev libgmp10 libssl-dev liblzma-dev
+sudo apt-get install -y libnuma-dev zlib1g-dev libgmp-dev libgmp10 libssl-dev liblzma-dev git wget
 
 . "$( cd "$(dirname "$0")" ; pwd -P )/../../ghcup_env"
 

.gitlab/script/ghcup_release.sh

@@ -10,13 +10,17 @@ ecabal() {
 	cabal --store-dir="$(pwd)"/.store "$@"
 }
 
+git describe
+
 # build
 ecabal update
 
 if [ "${OS}" = "LINUX" ] ; then
-	ecabal build -w ghc-${GHC_VERSION} -fcurl --ghc-options='-split-sections -optl-static'
+	ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections -optl-static'
+elif [ "${OS}" = "FREEBSD" ] ; then
+	ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections'
 else
-	ecabal build -w ghc-${GHC_VERSION} -fcurl
+	ecabal build -w ghc-${GHC_VERSION}
 fi
 
 mkdir out

.gitlab/script/ghcup_version.sh

@@ -14,15 +14,16 @@ eghcup() {
 	ghcup -v -c -s file://$(pwd)/ghcup-${JSON_VERSION}.json "$@"
 }
 
+git describe
 
 ### build
 
 ecabal update
 
 if [ "${OS}" = "DARWIN" ] ; then
-	ecabal build -w ghc-${GHC_VERSION} -fcurl
-else
 	ecabal build -w ghc-${GHC_VERSION}
+else
+	ecabal build -w ghc-${GHC_VERSION} -finternal-downloader
 fi
 
 cp "$(ecabal new-exec --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup')" .
@@ -70,7 +71,11 @@ ghci-$(ghc --numeric-version) --version
 
 # test installing new ghc doesn't mess with currently set GHC
 # https://gitlab.haskell.org/haskell/ghcup-hs/issues/7
-eghcup install 8.4.4
+if [ "${OS}" = "DARWIN" ] ; then
+	eghcup install 8.4.4
+else # test wget a bit
+	eghcup --downloader=wget install 8.4.4
+fi
 [ "$(ghc --numeric-version)" = "${ghc_ver}" ]
 eghcup set 8.4.4
 eghcup set 8.4.4

HACKING.md

@@ -43,3 +43,15 @@ Kazu Yamamoto [explained it in his PR](https://github.com/yesodweb/wai/pull/752#
 1. Brittany
 2. mtl-style preferred
 3. no overly pointfree style
+
+## Code structure
+
+Main functionality is in `GHCup` module. Utility functions are
+organised tree-ish in `GHCup.Utils` and `GHCup.Utils.*`.
+
+Anything dealing with ghcup specific directories is in
+`GHCup.Utils.Dirs`.
+
+Download information on where to fetch bindists from is in
+`GHCup.Data.GHCupDownloads`.
+

README.md

@@ -68,6 +68,15 @@ handles your haskell packages and can demand that [a specific version](https://c
 For man pages to work you need [man-db](http://man-db.nongnu.org/) as your `man` provider, then issue `man ghc`. Manpages only work for the currently set ghc.
 `MANPATH` may be required to be unset.
 
+### Shell-completion
+
+Shell completions are in `shell-completions`.
+
+For bash: install `shell-completions/bash`
+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).
+
 ## Design goals
 
 1. simplicity

RELEASING.md

@@ -4,8 +4,11 @@
 
 2. Add/fix downloads to `GHCupDownloads` module, then run `ghcup-gen gen` to generate the new json and validate it via `ghcup-gen check`.
 
-3. Commit and git push with tag. Wait for tests to succeed.
+3. Commit and git push with tag. Wait for tests to succeed and release artifacts to build.
 
-4. Upload the new `ghcup-<ver>.json` to `webhost.haskell.org/ghcup/data/`.
+4. Download release artifacts and upload them `downloads.haskell.org/ghcup`
+
+5. Add release artifacts to GHCupDownloads (see point 2.)
+
+6. Upload the final `ghcup-<ver>.json` to `webhost.haskell.org/ghcup/data/`.
 
-5. Build ghcup releases for Linux (fully static), mac (with `-fcurl`) and FreeBSD (with `-fcurl`). Upload to `webhost.haskell.org/ghcup/bin/` and update symlinks.

app/ghcup-gen/Main.hs

@@ -10,10 +10,10 @@
 
 module Main where
 
+import           GHCup.Data.GHCupInfo
 import           GHCup.Types
 import           GHCup.Types.JSON               ( )
 import           GHCup.Utils.Logger
-import           GHCupInfo
 
 import           Data.Aeson                     ( eitherDecode, encode )
 import           Data.Aeson.Encode.Pretty

app/ghcup-gen/Validate.hs

@@ -63,6 +63,7 @@ validate dls = do
 
     checkGHCisSemver
     forM_ (M.toList dls) $ \(t, _) -> checkMandatoryTags t
+    _ <- checkGHCHasBaseVersion
 
     -- exit
     e <- liftIO $ readIORef ref
@@ -105,8 +106,10 @@ validate dls = do
         lift $ $(logError) [i|Tags not unique for #{tool}: #{xs}|]
         addError
    where
-    isUniqueTag Latest      = True
-    isUniqueTag Recommended = True
+    isUniqueTag Latest         = True
+    isUniqueTag Recommended    = True
+    isUniqueTag (Base       _) = False
+    isUniqueTag (UnknownTag _) = False
 
   checkGHCisSemver = do
     let ghcVers = toListOf (ix GHC % to M.keys % folded) dls
@@ -125,6 +128,17 @@ validate dls = do
         addError
       True -> pure ()
 
+  -- all GHC versions must have a base tag
+  checkGHCHasBaseVersion = do
+    let allTags = M.toList $ availableToolVersions dls GHC
+    forM allTags $ \(ver, tags) -> case any isBase tags of
+      False -> do
+        lift $ $(logError) [i|Base tag missing from GHC ver #{ver}|]
+        addError
+      True -> pure ()
+
+  isBase (Base _) = True
+  isBase _        = False
 
 validateTarballs :: ( Monad m
                     , MonadLogger m
@@ -161,7 +175,7 @@ validateTarballs dls = do
 
  where
   downloadAll dli = do
-    let settings = Settings True False
+    let settings = Settings True False Never Curl
     let runLogger = myLoggerT LoggerConfig { lcPrintDebug = True
                                            , colorOutter  = B.hPut stderr
                                            , rawOutter    = (\_ -> pure ())

app/ghcup/Main.hs

@@ -32,7 +32,8 @@ import           Data.Bifunctor
 import           Data.Char
 import           Data.Either
 import           Data.Functor
-import           Data.List                      ( intercalate )
+import           Data.List                      ( intercalate, sort )
+import           Data.List.NonEmpty             (NonEmpty ((:|)))
 import           Data.Maybe
 import           Data.String.Interpolate
 import           Data.Text                      ( Text )
@@ -73,6 +74,8 @@ data Options = Options
   , optCache     :: Bool
   , optUrlSource :: Maybe URI
   , optNoVerify  :: Bool
+  , optKeepDirs  :: KeepDirs
+  , optsDownloader :: Downloader
   -- commands
   , optCommand   :: Command
   }
@@ -92,6 +95,10 @@ data Command
 data ToolVersion = ToolVersion Version
                  | ToolTag Tag
 
+prettyToolVer :: ToolVersion -> String
+prettyToolVer (ToolVersion v') = T.unpack $ prettyVer v'
+prettyToolVer (ToolTag t) = show t
+
 
 data InstallOptions = InstallOptions
   { instVer      :: Maybe ToolVersion
@@ -103,8 +110,9 @@ data SetGHCOptions = SetGHCOptions
   }
 
 data ListOptions = ListOptions
-  { lTool     :: Maybe Tool
-  , lCriteria :: Maybe ListCriteria
+  { lTool      :: Maybe Tool
+  , lCriteria  :: Maybe ListCriteria
+  , lRawFormat :: Bool
   }
 
 data RmOptions = RmOptions
@@ -158,6 +166,31 @@ opts =
           (short 'n' <> long "no-verify" <> help
             "Skip tarball checksum verification"
           )
+    <*> option
+          (eitherReader keepOnParser)
+          (  long "keep"
+          <> metavar "<always|errors|never>"
+          <> help
+               "Keep build directories? (default: never)"
+          <> value Never
+          <> hidden
+          )
+    <*> option
+          (eitherReader downloaderParser)
+          (  long "downloader"
+#if defined(INTERNAL_DOWNLOADER)
+          <> metavar "<internal|curl|wget>"
+          <> help
+          "Downloader to use (default: internal)"
+          <> value Internal
+#else
+          <> metavar "<curl|wget>"
+          <> help
+          "Downloader to use (default: curl)"
+          <> value Curl
+#endif
+          <> hidden
+          )
     <*> com
  where
   parseUri s' =
@@ -309,6 +342,9 @@ listOpts =
             )
           )
         )
+    <*> switch
+          (short 'r' <> long "raw-format" <> help "More machine-parsable format"
+          )
 
 rmOpts :: Parser RmOptions
 rmOpts = RmOptions <$> versionArgument
@@ -467,6 +503,9 @@ tagEither :: String -> Either String Tag
 tagEither s' = case fmap toLower s' of
   "recommended" -> Right Recommended
   "latest"      -> Right Latest
+  ('b':'a':'s':'e':'-':ver') -> case pvp (T.pack ver') of
+                                  Right x -> Right (Base x)
+                                  Left  _ -> Left [i|Invalid PVP version for base #{ver'}|]
   other         -> Left ([i|Unknown tag #{other}|])
 
 versionEither :: String -> Either String Version
@@ -495,6 +534,24 @@ criteriaParser s' | t == T.pack "installed" = Right ListInstalled
   where t = T.toLower (T.pack s')
 
 
+keepOnParser :: String -> Either String KeepDirs
+keepOnParser s' | t == T.pack "always" = Right Always
+                | t == T.pack "errors" = Right Errors
+                | t == T.pack "never"  = Right Never
+                | otherwise            = Left ("Unknown keep value: " <> s')
+  where t = T.toLower (T.pack s')
+
+
+downloaderParser :: String -> Either String Downloader
+downloaderParser s' | t == T.pack "curl"     = Right Curl
+                    | t == T.pack "wget"     = Right Wget
+#if defined(INTERNAL_DOWNLOADER)
+                    | t == T.pack "internal" = Right Internal
+#endif
+                    | otherwise = Left ("Unknown downloader value: " <> s')
+  where t = T.toLower (T.pack s')
+
+
 platformParser :: String -> Either String PlatformRequest
 platformParser s' = case MP.parse (platformP <* MP.eof) "" (T.pack s') of
   Right r -> pure r
@@ -570,8 +627,10 @@ platformParser s' = case MP.parse (platformP <* MP.eof) "" (T.pack s') of
 
 toSettings :: Options -> Settings
 toSettings Options {..} =
-  let cache    = optCache
-      noVerify = optNoVerify
+  let cache      = optCache
+      noVerify   = optNoVerify
+      keepDirs   = optKeepDirs
+      downloader = optsDownloader
   in  Settings { .. }
 
 
@@ -624,21 +683,31 @@ main = do
         <> help "Show the numeric version (for use in scripts)"
         <> hidden
         )
+  let listCommands = infoOption
+        "install set rm install-cabal list upgrade compile debug-info tool-requirements changelog"
+        (  long "list-commands"
+        <> help "List available commands for shell completion"
+        <> internal
+        )
 
   let main_footer = [i|Discussion:
   ghcup installs the Glasgow Haskell Compiler from the official
   release channels, enabling you to easily switch between different
-  versions.
+  versions. It maintains a self-contained ~/.ghcup directory.
+
+ENV variables:
+  * TMPDIR: where ghcup does the work (unpacking, building, ...)
+  * GHCUP_INSTALL_BASE_PREFIX: the base of ghcup (default: $HOME)
 
 Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
 
   customExecParser
       (prefs showHelpOnError)
-      (info (opts <**> helper <**> versionHelp <**> numericVersionHelp)
+      (info (opts <**> helper <**> versionHelp <**> numericVersionHelp <**> listCommands)
             (footerDoc (Just $ text main_footer))
       )
     >>= \opt@Options {..} -> do
-          let settings = toSettings opt
+          let settings@Settings{..} = toSettings opt
 
           -- create ~/.ghcup dir
           ghcdir <- ghcupBaseDir
@@ -749,9 +818,9 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
           (GHCupInfo treq dls) <-
             ( runLogger
               . flip runReaderT settings
-              . runE @'[JSONError , DownloadFailed]
+              . runE @'[JSONError , DownloadFailed, FileDoesNotExistError]
               $ liftE
-              $ getDownloads (maybe GHCupURL OwnSource optUrlSource)
+              $ getDownloadsF (maybe GHCupURL OwnSource optUrlSource)
               )
               >>= \case
                     VRight r -> pure r
@@ -776,10 +845,18 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                           [i|GHC ver #{prettyVer v} already installed|]
                         pure ExitSuccess
                       VLeft (V (BuildFailed tmpdir e)) -> do
-                        runLogger
-                          ($(logError) [i|Build failed with #{e}
-Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.|]
-                          )
+                        case keepDirs of
+                          Never -> runLogger ($(logError) [i|Build failed with #{e}|])
+                          _ -> runLogger ($(logError) [i|Build failed with #{e}
+Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
+Make sure to clean up #{tmpdir} afterwards.|])
+                        pure $ ExitFailure 3
+                      VLeft (V NoDownload) -> do
+
+                        runLogger $ do
+                          case instVer of
+                            Just iver -> $(logError) [i|No available GHC version for #{prettyToolVer iver}|]
+                            Nothing -> $(logError) [i|No available recommended GHC version|]
                         pure $ ExitFailure 3
                       VLeft e -> do
                         runLogger $ do
@@ -799,6 +876,13 @@ Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues
                         runLogger $ $(logWarn)
                           [i|Cabal ver #{prettyVer v} already installed|]
                         pure ExitSuccess
+                      VLeft (V NoDownload) -> do
+
+                        runLogger $ do
+                          case instVer of
+                            Just iver -> $(logError) [i|No available Cabal version for #{prettyToolVer iver}|]
+                            Nothing -> $(logError) [i|No available recommended Cabal version|]
+                        pure $ ExitFailure 4
                       VLeft e -> do
                         runLogger $ do
                           $(logError) [i|#{e}|]
@@ -827,7 +911,7 @@ Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues
                 )
                 >>= \case
                       VRight r -> do
-                        liftIO $ printListResult r
+                        liftIO $ printListResult lRawFormat r
                         pure ExitSuccess
                       VLeft e -> do
                         runLogger ($(logError) [i|#{e}|])
@@ -872,11 +956,11 @@ Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues
                           [i|GHC ver #{prettyVer v} already installed|]
                         pure ExitSuccess
                       VLeft (V (BuildFailed tmpdir e)) -> do
-                        runLogger
-                          ($(logError) [i|Build failed with #{e}
+                        case keepDirs of
+                          Never -> runLogger ($(logError) [i|Build failed with #{e}|])
+                          _ -> runLogger ($(logError) [i|Build failed with #{e}
 Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
-Make sure to clean up #{tmpdir} afterwards.|]
-                          )
+Make sure to clean up #{tmpdir} afterwards.|])
                         pure $ ExitFailure 9
                       VLeft e -> do
                         runLogger ($(logError) [i|#{e}|])
@@ -894,10 +978,11 @@ Make sure to clean up #{tmpdir} afterwards.|]
                           )
                         pure ExitSuccess
                       VLeft (V (BuildFailed tmpdir e)) -> do
-                        runLogger
-                          ($(logError) [i|Build failed with #{e}
-Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.|]
-                          )
+                        case keepDirs of
+                          Never -> runLogger ($(logError) [i|Build failed with #{e}|])
+                          _ -> runLogger ($(logError) [i|Build failed with #{e}
+Check the logs at ~/.ghcup/logs and the build directory #{tmpdir} for more clues.
+Make sure to clean up #{tmpdir} afterwards.|])
                         pure $ ExitFailure 10
                       VLeft e -> do
                         runLogger ($(logError) [i|#{e}|])
@@ -992,44 +1077,68 @@ fromVersion :: Monad m
             -> Excepts '[TagNotFound] m Version
 fromVersion av Nothing tool =
   getRecommended av tool ?? TagNotFound Recommended tool
-fromVersion _ (Just (ToolVersion v)) _ = pure v
+fromVersion av (Just (ToolVersion v)) _ = do
+  case pvp $ prettyVer v of
+    Left _ -> pure v
+    Right (PVP (major' :|[minor'])) ->
+      case getLatestGHCFor (fromIntegral major') (fromIntegral minor') av of
+        Just v' -> pure v'
+        Nothing -> pure v
+    Right _ -> pure v
 fromVersion av (Just (ToolTag Latest)) tool =
   getLatest av tool ?? TagNotFound Latest tool
 fromVersion av (Just (ToolTag Recommended)) tool =
   getRecommended av tool ?? TagNotFound Recommended tool
+fromVersion av (Just (ToolTag (Base pvp''))) GHC =
+  getLatestBaseVersion av pvp'' ?? TagNotFound (Base pvp'') GHC
+fromVersion _ (Just (ToolTag t')) tool =
+  throwE $ TagNotFound t' tool
 
 
-printListResult :: [ListResult] -> IO ()
-printListResult lr = do
+printListResult :: Bool -> [ListResult] -> IO ()
+printListResult raw lr = do
   -- https://gitlab.haskell.org/ghc/ghc/issues/8118
   setLocaleEncoding utf8
 
   let
     formatted =
       gridString
-          [ column expand left def def
-          , column expand left def def
-          , column expand left def def
-          , column expand left def def
-          , column expand left def def
-          ]
+          (  (if raw then [] else [column expand left def def])
+          ++ [ column expand left def def
+             , column expand left def def
+             , column expand left def def
+             , column expand left def def
+             ]
+          )
+        . (\x -> if raw
+            then x
+            else [color Green "", "Tool", "Version", "Tags", "Notes"] : x
+          )
         $ fmap
             (\ListResult {..} ->
-              [ if
-                | lSet       -> (color Green "✔✔")
-                | lInstalled -> (color Green "✓")
-                | otherwise  -> (color Red "✗")
-              , fmap toLower . show $ lTool
-              , T.unpack . prettyVer $ lVer
-              , intercalate "," $ ((fmap . fmap) toLower . fmap show $ lTag)
-              , intercalate "," $
-                (if fromSrc then [color Blue "compiled"] else mempty)
-                ++ (if lStray then [color Blue "stray"] else mempty)
-              ]
+              let marks = if
+                    | lSet       -> (color Green "✔✔")
+                    | lInstalled -> (color Green "✓")
+                    | otherwise  -> (color Red "✗")
+              in  (if raw then [] else [marks])
+                    ++ [ fmap toLower . show $ lTool
+                       , T.unpack . prettyVer $ lVer
+                       , intercalate "," $ (fmap printTag $ sort lTag)
+                       , intercalate ","
+                       $  (if fromSrc then [color' Blue "compiled"] else mempty)
+                       ++ (if lStray then [color' Blue "stray"] else mempty)
+                       ]
             )
             lr
   putStrLn $ formatted
-
+ where
+  printTag Recommended        = color' Green "recommended"
+  printTag Latest             = color' Yellow "latest"
+  printTag (Base pvp'') = "base-" ++ T.unpack (prettyPVP pvp'')
+  printTag (UnknownTag t    ) = t
+  color' = case raw of
+    True  -> flip const
+    False -> color
 
 checkForUpdates :: (MonadThrow m, MonadIO m, MonadFail m, MonadLogger m)
                 => GHCupDownloads

ghcup.cabal

@@ -21,8 +21,8 @@ source-repository head
   type:     git
   location: https://gitlab.haskell.org/haskell/ghcup-hs.git
 
-flag Curl
-  description: Use curl instead of http-io-streams for download
+flag internal-downloader
+  description: Compile the internal downloader, which links against OpenSSL
   default:     False
   manual:      True
 
@@ -279,6 +279,9 @@ library
 
   exposed-modules:
     GHCup
+    GHCup.Data.GHCupDownloads
+    GHCup.Data.GHCupInfo
+    GHCup.Data.ToolRequirements
     GHCup.Download
     GHCup.Download.Utils
     GHCup.Errors
@@ -301,15 +304,14 @@ library
   -- other-extensions:
   hs-source-dirs:  lib
 
-  if !flag(curl)
+  if flag(internal-downloader)
     import:
       , HsOpenSSL
       , http-io-streams
       , io-streams
       , terminal-progress-bar
     exposed-modules: GHCup.Download.IOStreams
-  else
-    cpp-options:     -DCURL
+    cpp-options:     -DINTERNAL_DOWNLOADER
 
 executable ghcup
   import:
@@ -344,6 +346,10 @@ executable ghcup
   hs-source-dirs:   app/ghcup
   default-language: Haskell2010
 
+  if flag(internal-downloader)
+    cpp-options:     -DINTERNAL_DOWNLOADER
+
+
 executable ghcup-gen
   import:
     config
@@ -372,9 +378,6 @@ executable ghcup-gen
   --
   main-is:          Main.hs
   other-modules:
-    GHCupDownloads
-    GHCupInfo
-    ToolRequirements
     Validate
 
   -- other-extensions:

lib/GHCup.hs

@@ -97,15 +97,15 @@ installGHCBin bDls ver mpfReq = do
   lift $ $(logDebug) [i|Requested to install GHC with #{ver}|]
   whenM (liftIO $ toolAlreadyInstalled GHC ver)
     $ (throwE $ AlreadyInstalled GHC ver)
-  Settings {..} <- lift ask
+  Settings {..}                <- lift ask
   pfreq@(PlatformRequest {..}) <- maybe (liftE $ platformRequest) pure mpfReq
 
   -- download (or use cached version)
-  dlinfo        <- lE $ getDownloadInfo GHC ver pfreq bDls
-  dl            <- liftE $ downloadCached dlinfo Nothing
+  dlinfo                       <- lE $ getDownloadInfo GHC ver pfreq bDls
+  dl                           <- liftE $ downloadCached dlinfo Nothing
 
   -- unpack
-  tmpUnpack     <- lift mkGhcupTmpDir
+  tmpUnpack                    <- lift mkGhcupTmpDir
   liftE $ unpackToDir tmpUnpack dl
   void $ liftIO $ darwinNotarization _rPlatform tmpUnpack
 
@@ -115,24 +115,12 @@ installGHCBin bDls ver mpfReq = do
   -- the subdir of the archive where we do the work
   let workdir = maybe tmpUnpack (tmpUnpack </>) (view dlSubdir dlinfo)
 
-  -- Be careful about cleanup. We must catch both pure exceptions
-  -- as well as async ones.
-  flip onException
-       (liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-    $ catchAllE
-        (\es -> do
-          liftIO (hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-            >> throwE (BuildFailed workdir es)
-        )
-    $ installGHC' workdir ghcdir
-
-  -- only clean up dir if the build succeeded
-  liftIO $ deleteDirRecursive tmpUnpack
+  liftE $ runBuildAction tmpUnpack (Just ghcdir) (installGHC' workdir ghcdir)
 
   liftE $ postGHCInstall ver
 
  where
-    -- | Install an unpacked GHC distribution. This only deals with the GHC build system and nothing else.
+  -- | Install an unpacked GHC distribution. This only deals with the GHC build system and nothing else.
   installGHC' :: (MonadLogger m, MonadIO m)
               => Path Abs      -- ^ Path to the unpacked GHC bindist (where the configure script resides)
               -> Path Abs      -- ^ Path to install to
@@ -195,7 +183,7 @@ installCabalBin bDls ver mpfReq = do
   pure ()
 
  where
-    -- | Install an unpacked cabal distribution.
+  -- | Install an unpacked cabal distribution.
   installCabal' :: (MonadLogger m, MonadCatch m, MonadIO m)
                 => Path Abs      -- ^ Path to the unpacked cabal bindist (where the executable resides)
                 -> Path Abs      -- ^ Path to install to
@@ -350,7 +338,7 @@ listVersions av lt criteria = case lt of
             -> m [ListResult]
   strayGHCs avTools = do
     ghcdir <- liftIO $ ghcupGHCBaseDir
-    fs     <- liftIO $ getDirsFiles' ghcdir
+    fs     <- liftIO $ liftIO $ hideErrorDef [NoSuchThing] [] $ getDirsFiles' ghcdir
     fmap catMaybes $ forM fs $ \(toFilePath -> f) -> do
       case version . decUTF8Safe $ f of
         Right v' -> do
@@ -533,20 +521,10 @@ compileGHC dls tver bstrap jobs mbuildConfig patchdir = do
   let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
   ghcdir <- liftIO $ ghcupGHCDir tver
 
-  -- Be careful about cleanup. We must catch both pure exceptions
-  -- as well as async ones.
-  flip onException
-       (liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-    $ catchAllE
-        (\es ->
-          liftIO (hideError doesNotExistErrorType $ deleteDirRecursive ghcdir)
-            >> throwE (BuildFailed workdir es)
-        )
-    $ compile bghc ghcdir workdir
-  markSrcBuilt ghcdir workdir
-
-  -- only clean up dir if the build succeeded
-  liftIO $ deleteDirRecursive tmpUnpack
+  liftE $ runBuildAction
+    tmpUnpack
+    (Just ghcdir)
+    (compile bghc ghcdir workdir >> markSrcBuilt ghcdir workdir)
 
   reThrowAll GHCupSetError $ postGHCInstall tver
   pure ()
@@ -666,7 +644,11 @@ compileCabal dls tver bghc jobs patchdir = do
 
   let workdir = maybe id (flip (</>)) (view dlSubdir dlInfo) $ tmpUnpack
 
-  reThrowAll (BuildFailed workdir) $ compile workdir
+
+  liftE $ runBuildAction
+    tmpUnpack
+    Nothing
+    (compile workdir)
 
   -- only clean up dir if the build succeeded
   liftIO $ deleteDirRecursive tmpUnpack

lib/GHCup/Data/GHCupDownloads.hs

@@ -2,7 +2,7 @@
 {-# LANGUAGE QuasiQuotes       #-}
 
 
-module GHCupDownloads where
+module GHCup.Data.GHCupDownloads where
 
 import           GHCup.Types
 import           GHCup.Utils.Version.QQ
@@ -951,6 +951,24 @@ cabal_3000_64_darwin = DownloadInfo
   Nothing
   "d4857e068560515e4cbb0e8ca124c370e07892f2a28804d87152834e5fe2b845"
 
+cabal_3000_64_freebsd :: DownloadInfo
+cabal_3000_64_freebsd = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-x86_64-portbld-freebsd.tar.xz&dl=1|]
+  Nothing
+  "d97b6469ed612a1367ad1032d0722469ee5277668879694d7d4336233b937516"
+
+cabal_3000_32_alpine :: DownloadInfo
+cabal_3000_32_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-i386-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "a4191cd5a645b00e6a9c53abe6f3cb91fe700de7d7c520c9cb36ce8ec5c9919a"
+
+cabal_3000_64_alpine :: DownloadInfo
+cabal_3000_64_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.0.0.0-x86_64-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "7b35e5986aba4a40fc37141cbde26612bfc916e95a2d2ff35a413612d8c7cd3a"
+
 
 
     ---------------------
@@ -976,6 +994,24 @@ cabal_3200_64_darwin = DownloadInfo
   Nothing
   "9197c17d2ece0f934f5b33e323cfcaf486e4681952687bc3d249488ce3cbe0e9"
 
+cabal_3200_64_freebsd :: DownloadInfo
+cabal_3200_64_freebsd = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-portbld-freebsd.tar.xz&dl=1|]
+  Nothing
+  "e4dc00ab7fef51354e7624dd03e49c6bb684887fc95acb9b33bc52f357a5ef8c"
+
+cabal_3200_32_alpine :: DownloadInfo
+cabal_3200_32_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-i386-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "4aaa52fbc337ae1ef855a2aa2808186580b21ec36883aafec7473e7d899bc5ec"
+
+cabal_3200_64_alpine :: DownloadInfo
+cabal_3200_64_alpine = DownloadInfo
+  [uri|https://hasufell.de/d/d3e215db133e4fcaa61e/files/?p=/cabal-install-3.2.0.0-x86_64-alpine-linux-musl.tar.xz&dl=1|]
+  Nothing
+  "c1f3c21a5307cea8d2a0bd9a2eab9f56f3dd90e947ae64e231f909024980992b"
+
 
 
 
@@ -1026,7 +1062,7 @@ ghcupDownloads = M.fromList
     , M.fromList
       [ ( [vver|7.10.3|]
         , VersionInfo
-            []
+            [Base [pver|4.8.2.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/7.10.3/docs/html/users_guide/release-7-10-1.html|]
             )
@@ -1072,7 +1108,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.0.2|]
         , VersionInfo
-            []
+            [Base [pver|4.9.1.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.0.2/docs/html/users_guide/8.0.1-notes.html|]
             )
@@ -1118,7 +1154,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.2.2|]
         , VersionInfo
-            []
+            [Base [pver|4.10.1.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.2.2/docs/html/users_guide/8.2.2-notes.html|]
             )
@@ -1170,7 +1206,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.4.1|]
         , VersionInfo
-            []
+            [Base [pver|4.11.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.4.1/docs/html/users_guide/8.4.1-notes.html|]
             )
@@ -1209,7 +1245,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.4.2|]
         , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.4.2/docs/html/users_guide/8.4.2-notes.html|]
             )
@@ -1259,7 +1295,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.4.3|]
         , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.4.3/docs/html/users_guide/8.4.3-notes.html|]
             )
@@ -1308,7 +1344,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.4.4|]
         , VersionInfo
-            []
+            [Base [pver|4.11.1.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.4.4/docs/html/users_guide/8.4.4-notes.html|]
             )
@@ -1362,7 +1398,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.6.1|]
         , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.6.1/docs/html/users_guide/8.6.1-notes.html|]
             )
@@ -1412,7 +1448,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.6.2|]
         , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.6.2/docs/html/users_guide/8.6.2-notes.html|]
             )
@@ -1456,7 +1492,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.6.3|]
         , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.6.3/docs/html/users_guide/8.6.3-notes.html|]
             )
@@ -1510,7 +1546,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.6.4|]
         , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.6.4/docs/html/users_guide/8.6.4-notes.html|]
             )
@@ -1559,7 +1595,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.6.5|]
         , VersionInfo
-            []
+            [Base [pver|4.12.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.6.5/docs/html/users_guide/8.6.5-notes.html|]
             )
@@ -1612,7 +1648,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.8.1|]
         , VersionInfo
-            []
+            [Base [pver|4.13.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.8.1/docs/html/users_guide/8.8.1-notes.html|]
             )
@@ -1665,7 +1701,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.8.2|]
         , VersionInfo
-            []
+            [Base [pver|4.13.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.8.2/docs/html/users_guide/8.8.2-notes.html|]
             )
@@ -1718,7 +1754,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.8.3|]
         , VersionInfo
-            [Recommended]
+            [Recommended, Base [pver|4.13.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.8.3/docs/html/users_guide/8.8.3-notes.html|]
             )
@@ -1771,7 +1807,7 @@ ghcupDownloads = M.fromList
         )
       , ( [vver|8.10.1|]
         , VersionInfo
-            [Latest]
+            [Latest, Base [pver|4.14.0.0|]]
             (Just
               [uri|https://downloads.haskell.org/ghc/8.10.1/docs/html/users_guide/8.10.1-notes.html|]
             )
@@ -1889,7 +1925,9 @@ ghcupDownloads = M.fromList
                   [ ( Linux UnknownLinux
                     , M.fromList [(Nothing, cabal_3000_64_linux)]
                     )
-                  , (Darwin, M.fromList [(Nothing, cabal_3000_64_darwin)])
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3000_64_alpine)])
+                  , (Darwin      , M.fromList [(Nothing, cabal_3000_64_darwin)])
+                  , (FreeBSD, M.fromList [(Nothing, cabal_3000_64_freebsd)])
                   ]
                 )
               , ( A_32
@@ -1897,6 +1935,7 @@ ghcupDownloads = M.fromList
                   [ ( Linux UnknownLinux
                     , M.fromList [(Nothing, cabal_3000_32_linux)]
                     )
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3000_32_alpine)])
                   ]
                 )
               ]
@@ -1918,7 +1957,9 @@ ghcupDownloads = M.fromList
                   [ ( Linux UnknownLinux
                     , M.fromList [(Nothing, cabal_3200_64_linux)]
                     )
-                  , (Darwin, M.fromList [(Nothing, cabal_3200_64_darwin)])
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3200_64_alpine)])
+                  , (Darwin      , M.fromList [(Nothing, cabal_3200_64_darwin)])
+                  , (FreeBSD, M.fromList [(Nothing, cabal_3200_64_freebsd)])
                   ]
                 )
               , ( A_32
@@ -1926,6 +1967,7 @@ ghcupDownloads = M.fromList
                   [ ( Linux UnknownLinux
                     , M.fromList [(Nothing, cabal_3200_32_linux)]
                     )
+                  , (Linux Alpine, M.fromList [(Nothing, cabal_3200_32_alpine)])
                   ]
                 )
               ]

lib/GHCup/Data/GHCupInfo.hs

@@ -1,7 +1,7 @@
-module GHCupInfo where
+module GHCup.Data.GHCupInfo where
 
-import           GHCupDownloads
-import           ToolRequirements
+import           GHCup.Data.GHCupDownloads
+import           GHCup.Data.ToolRequirements
 import           GHCup.Types
 
 

lib/GHCup/Data/ToolRequirements.hs

@@ -1,10 +1,11 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE QuasiQuotes       #-}
 
-module ToolRequirements where
+module GHCup.Data.ToolRequirements where
 
 import           GHCup.Types
 import           GHCup.Utils.String.QQ
+import           GHCup.Utils.Version.QQ
 
 import qualified Data.Map                      as M
 
@@ -61,6 +62,35 @@ toolRequirements = M.fromList
                 )
               ]
             )
+          , ( Linux CentOS
+            , M.fromList
+              [ ( Nothing
+                , Requirements
+                  [ "gcc"
+                  , "gcc-c++"
+                  , "gmp"
+                  , "make"
+                  , "ncurses"
+                  , "ncurses-compat-libs"
+                  , "xz"
+                  , "perl"
+                  ]
+                  ""
+                ),
+              ( Just [vers|7|]
+                , Requirements
+                  [ "gcc"
+                  , "gcc-c++"
+                  , "gmp"
+                  , "make"
+                  , "ncurses"
+                  , "xz"
+                  , "perl"
+                  ]
+                  ""
+                )
+              ]
+            )
           , ( Darwin
             , M.fromList
               [ ( Nothing

lib/GHCup/Download.hs

@@ -11,7 +11,7 @@
 
 module GHCup.Download where
 
-#if !defined(CURL)
+#if defined(INTERNAL_DOWNLOADER)
 import           GHCup.Download.IOStreams
 import           GHCup.Download.Utils
 #endif
@@ -35,7 +35,7 @@ import           Control.Monad.Reader
 import           Control.Monad.Trans.Resource
                                          hiding ( throwM )
 import           Data.Aeson
-#if !defined(CURL)
+#if defined(INTERNAL_DOWNLOADER)
 import           Data.ByteString                ( ByteString )
 import           Data.CaseInsensitive           ( CI )
 #endif
@@ -43,10 +43,11 @@ import           Data.Maybe
 import           Data.String.Interpolate
 import           Data.Time.Clock
 import           Data.Time.Clock.POSIX
-#if !defined(CURL)
+#if defined(INTERNAL_DOWNLOADER)
 import           Data.Time.Format
 #endif
 import           Data.Versions
+import           Data.Word8
 import           GHC.IO.Exception
 import           HPath
 import           HPath.IO                      as HIO
@@ -57,12 +58,14 @@ import           Prelude                 hiding ( abs
                                                 , writeFile
                                                 )
 import           System.IO.Error
+import           System.Posix.Env.ByteString    ( getEnv )
 import           URI.ByteString
 
 import qualified Crypto.Hash.SHA256            as SHA256
+import qualified Data.ByteString               as BS
 import qualified Data.ByteString.Base16        as B16
 import qualified Data.ByteString.Lazy          as L
-#if !defined(CURL)
+#if defined(INTERNAL_DOWNLOADER)
 import qualified Data.CaseInsensitive          as CI
 import qualified Data.Map.Strict               as M
 import qualified Data.Text                     as T
@@ -82,6 +85,48 @@ import qualified System.Posix.RawFilePath.Directory
     ------------------
 
 
+-- | Like 'getDownloads', but tries to fall back to
+-- cached ~/.ghcup/cache/ghcup-<format-ver>.json
+getDownloadsF :: ( FromJSONKey Tool
+                 , FromJSONKey Version
+                 , FromJSON VersionInfo
+                 , MonadIO m
+                 , MonadCatch m
+                 , MonadLogger m
+                 , MonadThrow m
+                 , MonadFail m
+                 , MonadReader Settings m
+                 )
+              => URLSource
+              -> Excepts
+                   '[JSONError , DownloadFailed , FileDoesNotExistError]
+                   m
+                   GHCupInfo
+getDownloadsF urlSource = do
+  case urlSource of
+    GHCupURL ->
+      liftE
+        $ handleIO (\_ -> readFromCache)
+        $ catchE @_ @'[JSONError , FileDoesNotExistError]
+            (\(DownloadFailed _) -> readFromCache)
+        $ getDownloads urlSource
+    (OwnSource _) -> liftE $ getDownloads urlSource
+    (OwnSpec   _) -> liftE $ getDownloads urlSource
+ where
+  readFromCache = do
+    lift $ $(logWarn)
+      [i|Could not get download info, trying cached version (this may not be recent!)|]
+    let path = view pathL' ghcupURL
+    cacheDir  <- liftIO $ ghcupCacheDir
+    json_file <- (cacheDir </>) <$> urlBaseName path
+    bs        <-
+      handleIO' NoSuchThing
+                (\_ -> throwE $ FileDoesNotExistError (toFilePath json_file))
+      $ liftIO
+      $ readFile json_file
+    lE' JSONDecodeError $ eitherDecode' bs
+
+
 -- | Downloads the download information! But only if we need to ;P
 getDownloads :: ( FromJSONKey Tool
                 , FromJSONKey Version
@@ -91,6 +136,7 @@ getDownloads :: ( FromJSONKey Tool
                 , MonadLogger m
                 , MonadThrow m
                 , MonadFail m
+                , MonadReader Settings m
                 )
              => URLSource
              -> Excepts '[JSONError , DownloadFailed] m GHCupInfo
@@ -116,7 +162,12 @@ getDownloads urlSource = do
   --
   -- Always save the local file with the mod time of the remote file.
   smartDl :: forall m1
-           . (MonadCatch m1, MonadIO m1, MonadFail m1, MonadLogger m1)
+           . ( MonadCatch m1
+             , MonadIO m1
+             , MonadFail m1
+             , MonadLogger m1
+             , MonadReader Settings m1
+             )
           => URI
           -> Excepts
                '[ FileDoesNotExistError
@@ -148,31 +199,38 @@ getDownloads urlSource = do
               Just modTime -> do
                 fileMod <- liftIO $ getModificationTime json_file
                 if modTime > fileMod
-                  then do
-                    bs <- liftE $ downloadBS uri'
-                    liftIO $ writeFileWithModTime modTime json_file bs
-                    pure bs
+                  then dlWithMod modTime json_file
                   else liftIO $ readFile json_file
               Nothing -> do
                 lift $ $(logDebug) [i|Unable to get/parse Last-Modified header|]
-                liftIO $ deleteFile json_file
-                liftE $ downloadBS uri'
+                dlWithoutMod json_file
           else -- access in less than 5 minutes, re-use file
                liftIO $ readFile json_file
       else do
         liftIO $ createDirIfMissing newDirPerms cacheDir
         getModTime >>= \case
-          Just modTime -> do
-            bs <- liftE $ downloadBS uri'
-            liftIO $ writeFileWithModTime modTime json_file bs
-            pure bs
+          Just modTime -> dlWithMod modTime json_file
           Nothing -> do
+            -- although we don't know last-modified, we still save
+            -- it to a file, so we might use it in offline mode
             lift $ $(logDebug) [i|Unable to get/parse Last-Modified header|]
-            liftE $ downloadBS uri'
+            dlWithoutMod json_file
 
    where
+    dlWithMod modTime json_file = do
+      bs <- liftE $ downloadBS uri'
+      liftIO $ writeFileWithModTime modTime json_file bs
+      pure bs
+    dlWithoutMod json_file = do
+      bs <- liftE $ downloadBS uri'
+      liftIO $ hideError doesNotExistErrorType $ deleteFile json_file
+      liftIO $ writeFileL json_file (Just newFilePerms) bs
+      liftIO $ setModificationTime json_file (fromIntegral @Int 0)
+      pure bs
+
+
     getModTime = do
-#if defined(CURL)
+#if !defined(INTERNAL_DOWNLOADER)
       pure Nothing
 #else
       headers <-
@@ -271,12 +329,19 @@ download dli dest mfn
             (liftIO $ hideError doesNotExistErrorType $ deleteFile destFile)
               >> (throwE . DownloadFailed $ e)
           ) $ do
-#if defined(CURL)
-              liftE $ lEM @_ @'[ProcessError] $ liftIO $ exec "curl" True
-                ["-fL", "-o", toFilePath destFile , serializeURIRef' $ view dlUri dli] Nothing Nothing
-#else
-              (https, host, fullPath, port) <- liftE $ uriToQuadruple (view dlUri dli)
-              liftE $ downloadToFile https host fullPath port destFile
+              lift getDownloader >>= \case
+                Curl -> do
+                  o' <- liftIO getCurlOpts
+                  liftE $ lEM @_ @'[ProcessError] $ liftIO $ exec "curl" True
+                    (o' ++ ["-fL", "-o", toFilePath destFile, serializeURIRef' $ view dlUri dli]) Nothing Nothing
+                Wget -> do
+                  o' <- liftIO getWgetOpts
+                  liftE $ lEM @_ @'[ProcessError] $ liftIO $ exec "wget" True
+                    (o' ++ ["-O", toFilePath destFile , serializeURIRef' $ view dlUri dli]) Nothing Nothing
+#if defined(INTERNAL_DOWNLOADER)
+                Internal -> do
+                  (https, host, fullPath, port) <- liftE $ uriToQuadruple (view dlUri dli)
+                  liftE $ downloadToFile https host fullPath port destFile
 #endif
 
     liftE $ checkDigest dli destFile
@@ -329,7 +394,7 @@ downloadCached dli mfn = do
 
 
 -- | This is used for downloading the JSON.
-downloadBS :: (MonadCatch m, MonadIO m)
+downloadBS :: (MonadReader Settings m, MonadCatch m, MonadIO m, MonadLogger m)
            => URI
            -> Excepts
                 '[ FileDoesNotExistError
@@ -356,18 +421,33 @@ downloadBS uri'
  where
   scheme = view (uriSchemeL' % schemeBSL') uri'
   path   = view pathL' uri'
-#if defined(CURL)
-  dl _ = do
-    let exe = [rel|curl|]
-        args = ["-sSfL", serializeURIRef' uri']
-    liftIO (executeOut exe args Nothing) >>= \case
-      CapturedProcess ExitSuccess stdout _ -> do
-        pure $ L.fromStrict stdout
-      CapturedProcess (ExitFailure i') _ _ -> throwE $ NonZeroExit i' (toFilePath exe) args
-#else
+#if defined(INTERNAL_DOWNLOADER)
   dl https = do
-    (_, host', fullPath', port') <- liftE $ uriToQuadruple uri'
-    liftE $ downloadBS' https host' fullPath' port'
+#else
+  dl _ = do
+#endif
+    lift $ $(logDebug) [i|downloading: #{serializeURIRef' uri'}|]
+    lift getDownloader >>= \case
+      Curl -> do
+        o' <- liftIO getCurlOpts
+        let exe = [rel|curl|]
+            args = o' ++ ["-sSfL", serializeURIRef' uri']
+        liftIO (executeOut exe args Nothing) >>= \case
+          CapturedProcess ExitSuccess stdout _ -> do
+            pure $ L.fromStrict stdout
+          CapturedProcess (ExitFailure i') _ _ -> throwE $ NonZeroExit i' (toFilePath exe) args
+      Wget -> do
+        o' <- liftIO getWgetOpts
+        let exe = [rel|wget|]
+            args = o' ++ ["-qO-", serializeURIRef' uri']
+        liftIO (executeOut exe args Nothing) >>= \case
+          CapturedProcess ExitSuccess stdout _ -> do
+            pure $ L.fromStrict stdout
+          CapturedProcess (ExitFailure i') _ _ -> throwE $ NonZeroExit i' (toFilePath exe) args
+#if defined(INTERNAL_DOWNLOADER)
+      Internal -> do
+        (_, host', fullPath', port') <- liftE $ uriToQuadruple uri'
+        liftE $ downloadBS' https host' fullPath' port'
 #endif
 
 
@@ -385,3 +465,19 @@ checkDigest dli file = do
     let eDigest = view dlHash dli
     when ((cDigest /= eDigest) && verify) $ throwE (DigestError cDigest eDigest)
 
+
+-- | Get additional curl args from env. This is an undocumented option.
+getCurlOpts :: IO [ByteString]
+getCurlOpts =
+  getEnv "GHCUP_CURL_OPTS" >>= \case
+    Just r  -> pure $ BS.split _space r
+    Nothing -> pure []
+
+
+-- | Get additional wget args from env. This is an undocumented option.
+getWgetOpts :: IO [ByteString]
+getWgetOpts =
+  getEnv "GHCUP_WGET_OPTS" >>= \case
+    Just r  -> pure $ BS.split _space r
+    Nothing -> pure []
+

lib/GHCup/Types.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP           #-}
 {-# LANGUAGE DeriveGeneric #-}
 
 module GHCup.Types where
@@ -81,7 +82,9 @@ data VersionInfo = VersionInfo
 -- | A tag. These are currently attached to a version of a tool.
 data Tag = Latest
          | Recommended
-         deriving (Ord, Eq, Show)
+         | Base PVP
+         | UnknownTag String  -- ^ used for upwardscompat
+         deriving (Ord, Eq, Show) -- FIXME: manual JSON instance
 
 
 data Architecture = A_64
@@ -138,12 +141,26 @@ data URLSource = GHCupURL
 
 
 data Settings = Settings
-  { cache    :: Bool
-  , noVerify :: Bool
+  { cache      :: Bool
+  , noVerify   :: Bool
+  , keepDirs   :: KeepDirs
+  , downloader :: Downloader
   }
   deriving Show
 
 
+data KeepDirs = Always
+              | Errors
+              | Never
+  deriving (Eq, Show, Ord)
+
+data Downloader = Curl
+                | Wget
+#if defined(INTERNAL_DOWNLOADER)
+                | Internal
+#endif
+  deriving (Eq, Show, Ord)
+
 data DebugInfo = DebugInfo
   { diBaseDir  :: Path Abs
   , diBinDir   :: Path Abs

lib/GHCup/Types/JSON.hs

@@ -37,11 +37,24 @@ deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Tool
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VSep
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VUnit
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''VersionInfo
-deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Tag
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''DownloadInfo
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''GHCupInfo
 deriveJSON defaultOptions { fieldLabelModifier = removeLensFieldLabel } ''Requirements
 
+instance ToJSON Tag where
+  toJSON Latest = String "Latest"
+  toJSON Recommended = String "Recommended"
+  toJSON (Base pvp'') = String ("base-" <> prettyPVP pvp'')
+  toJSON (UnknownTag x) = String (T.pack x)
+
+instance FromJSON Tag where
+  parseJSON = withText "Tag" $ \t -> case T.unpack t of
+    "Latest" -> pure Latest
+    "Recommended" -> pure Recommended
+    ('b':'a':'s':'e':'-':ver') -> case pvp (T.pack ver') of
+                                    Right x -> pure $ Base x
+                                    Left e -> fail . show $ e
+    x -> pure (UnknownTag x)
 
 instance ToJSON URI where
   toJSON = toJSON . decUTF8Safe . serializeURIRef'
@@ -143,6 +156,14 @@ instance FromJSONKey Version where
     Right x -> pure x
     Left  e -> fail $ "Failure in Version (FromJSONKey)" <> show e
 
+instance ToJSON PVP where
+  toJSON = toJSON . prettyPVP
+
+instance FromJSON PVP where
+  parseJSON = withText "PVP" $ \t -> case pvp t of
+    Right x -> pure x
+    Left  e -> fail $ "Failure in PVP (FromJSON)" <> show e
+
 instance ToJSONKey Tool where
   toJSONKey = genericToJSONKey defaultJSONKeyOptions
 

lib/GHCup/Utils.hs

@@ -222,6 +222,23 @@ getGHCForMajor major' minor' = do
     $ semvers
 
 
+-- | Get the latest available ghc for X.Y major version.
+getLatestGHCFor :: Int -- ^ major version component
+                -> Int -- ^ minor version component
+                -> GHCupDownloads
+                -> Maybe Version
+getLatestGHCFor major' minor' dls = do
+  join . fmap
+      (lastMay . filter
+        (\v -> case semver $ prettyVer v of
+                 Right SemVer{..} -> fromIntegral _svMajor == major' && fromIntegral _svMinor == minor'
+                 Left _ -> False
+        )
+      )
+    . preview (ix GHC % to Map.keys) $ dls
+
+
+
 
 
     -----------------
@@ -279,6 +296,11 @@ getRecommended :: GHCupDownloads -> Tool -> Maybe Version
 getRecommended av tool = headOf (ix tool % getTagged Recommended % to fst) $ av
 
 
+-- | Gets the latest GHC with a given base version.
+getLatestBaseVersion :: GHCupDownloads -> PVP -> Maybe Version
+getLatestBaseVersion av pvpVer = headOf (ix GHC % getTagged (Base pvpVer) % to fst) av
+
+
 
     -----------------------
     --[ Settings Getter ]--
@@ -289,6 +311,10 @@ getCache :: MonadReader Settings m => m Bool
 getCache = ask <&> cache
 
 
+getDownloader :: MonadReader Settings m => m Downloader
+getDownloader = ask <&> downloader
+
+
 
     -------------
     --[ Other ]--
@@ -384,3 +410,40 @@ getChangeLog dls tool (Right tag) = preview
   % viChangeLog
   % _Just
   ) dls
+
+
+-- | Execute a build action while potentially cleaning up:
+--
+--   1. the build directory, depending on the KeepDirs setting
+--   2. the install destination, depending on whether the build failed
+runBuildAction :: (Show (V e), MonadReader Settings m, MonadIO m, MonadMask m)
+               => Path Abs          -- ^ build directory
+               -> Maybe (Path Abs)  -- ^ install location (e.g. for GHC)
+               -> Excepts e m ()
+               -> Excepts '[BuildFailed] m ()
+runBuildAction bdir instdir action = do
+  Settings {..} <- lift ask
+  flip
+      onException
+      (do
+        forM_ instdir $ \dir ->
+          liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
+        when (keepDirs == Never)
+          $ liftIO
+          $ hideError doesNotExistErrorType
+          $ deleteDirRecursive bdir
+      )
+    $ catchAllE
+        (\es -> do
+          forM_ instdir $ \dir ->
+            liftIO $ hideError doesNotExistErrorType $ deleteDirRecursive dir
+          when (keepDirs == Never)
+            $ liftIO
+            $ hideError doesNotExistErrorType
+            $ deleteDirRecursive bdir
+          throwE (BuildFailed bdir es)
+        )
+    $ action
+
+  when (keepDirs == Never || keepDirs == Errors) $ liftIO $ deleteDirRecursive
+    bdir

lib/GHCup/Utils/File.hs

@@ -199,6 +199,7 @@ execLogged exe spath args lfile chdir env = do
     lineAction ref rs bs' = do
       modifyIORef' ref (swapRegs bs')
       regs <- readIORef ref
+      void $ SPIB.fdWrite fileFd (bs' <> "\n")
       forM (zip regs rs) $ \(bs, r) -> do
         setConsoleRegion r $ do
           w <- consoleWidth
@@ -210,8 +211,6 @@ execLogged exe spath args lfile chdir env = do
             . trim w
             . (\b -> "[ " <> toFilePath lfile <> " ] " <> b)
             $ bs
-        SPIB.fdWrite fileFd (bs <> "\n")
-
 
     swapRegs bs regs | length regs < size = regs ++ [bs]
                      | otherwise          = tail regs ++ [bs]

lib/GHCup/Version.hs

@@ -13,7 +13,7 @@ import qualified Data.Text                     as T
 
 -- | This reflects the API version of the JSON.
 ghcupURL :: URI
-ghcupURL = [uri|https://www.haskell.org/ghcup/data/ghcup-0.0.1.json|]
+ghcupURL = [uri|https://www.haskell.org/ghcup/data/ghcup-0.0.2.json|]
 
 ghcUpVer :: PVP
 ghcUpVer = [pver|0.1.4|]

shell-completions/bash

@@ -0,0 +1,14 @@
+_ghcup()
+{
+    local CMDLINE
+    local IFS=$'\n'
+    CMDLINE=(--bash-completion-index $COMP_CWORD)
+
+    for arg in ${COMP_WORDS[@]}; do
+        CMDLINE=(${CMDLINE[@]} --bash-completion-word $arg)
+    done
+
+    COMPREPLY=( $(ghcup "${CMDLINE[@]}") )
+}
+
+complete -o filenames -F _ghcup ghcup

shell-completions/fish

@@ -0,0 +1,19 @@
+ function _ghcup
+    set -l cl (commandline --tokenize --current-process)
+    # Hack around fish issue #3934
+    set -l cn (commandline --tokenize --cut-at-cursor --current-process)
+    set -l cn (count $cn)
+    set -l tmpline --bash-completion-enriched --bash-completion-index $cn
+    for arg in $cl
+      set tmpline $tmpline --bash-completion-word $arg
+    end
+    for opt in (ghcup $tmpline)
+      if test -d $opt
+        echo -E "$opt/"
+      else
+        echo -E "$opt"
+      end
+    end
+end
+
+complete --no-files --command ghcup --arguments '(_ghcup)'

shell-completions/zsh

@@ -0,0 +1,32 @@
+#compdef ghcup
+
+local request
+local completions
+local word
+local index=$((CURRENT - 1))
+
+request=(--bash-completion-enriched --bash-completion-index $index)
+for arg in ${words[@]}; do
+  request=(${request[@]} --bash-completion-word $arg)
+done
+
+IFS=$'\n' completions=($( ghcup "${request[@]}" ))
+
+for word in $completions; do
+  local -a parts
+
+  # Split the line at a tab if there is one.
+  IFS=$'\t' parts=($( echo $word ))
+
+  if [[ -n $parts[2] ]]; then
+     if [[ $word[1] == "-" ]]; then
+       local desc=("$parts[1] ($parts[2])")
+       compadd -d desc -- $parts[1]
+     else
+       local desc=($(print -f  "%-019s -- %s" $parts[1] $parts[2]))
+       compadd -l -d desc -- $parts[1]
+     fi
+  else
+    compadd -f -- $word
+  fi
+done