Improve style

Fixes #32

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

@@ -18,14 +18,12 @@ apk add --no-cache \
 	tar \
 	perl
 
-ln -sf libncurses.so /usr/lib/libtinfo.so
+ln -s libncurses.so /usr/lib/libtinfo.so
-ln -sf libncursesw.so.6 /usr/lib/libtinfow.so.6
+ln -s libncursesw.so.6 /usr/lib/libtinfow.so.6
-ln -sf libtinfow.so.6 /usr/lib/libtinfow.so
-
 if [ "${BIT}" = "32" ] ; then
-	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.5/i386-linux-ghcup-0.1.5 > ./ghcup-bin
+	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.4/i386-linux-ghcup-0.1.4 > ./ghcup-bin
 else
-	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.5/x86_64-linux-ghcup-0.1.5 > ./ghcup-bin
+	curl -sSfL https://downloads.haskell.org/~ghcup/0.1.4/x86_64-linux-ghcup-0.1.4 > ./ghcup-bin
 fi
 chmod +x ghcup-bin
 ./ghcup-bin upgrade
@@ -59,8 +57,7 @@ apk add --no-cache \
 	openssl-dev \
 	openssl-libs-static \
 	xz \
-	xz-dev \
+	xz-dev
-	ncurses-static
+
 
-ln -sf libncursesw.a /usr/lib/libtinfow.a
 

.gitlab/script/ghcup_release.sh

@@ -16,24 +16,16 @@ git describe
 ecabal update
 
 if [ "${OS}" = "LINUX" ] ; then
-	if [ "${BIT}" = "32" ] ; then
+	ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections -optl-static'
-		ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections -optl-static'
-	else
-		ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections -optl-static' -ftui
-	fi
 elif [ "${OS}" = "FREEBSD" ] ; then
 	ecabal build -w ghc-${GHC_VERSION} --ghc-options='-split-sections' --constraint="zlib static"
 else
-	ecabal build -w ghc-${GHC_VERSION} --constraint="zlib static" --constraint="lzma static" -ftui
+	ecabal build -w ghc-${GHC_VERSION} --constraint="zlib static" --constraint="lzma static"
 fi
 
 mkdir out
 cp "$(ecabal new-exec -w ghc-${GHC_VERSION} --verbose=0 --offline sh -- -c 'command -v ghcup')" .
 ver=$(./ghcup --numeric-version)
-if [ "${OS}" = "DARWIN" ] ; then
+strip -s ./ghcup
-	strip ./ghcup
-else
-	strip -s ./ghcup
-fi
 cp ghcup out/${ARTIFACT}-${ver}
 

.gitlab/script/ghcup_version.sh

@@ -21,9 +21,9 @@ git describe --always
 ecabal update
 
 if [ "${OS}" = "DARWIN" ] ; then
-	ecabal build -w ghc-${GHC_VERSION} -ftui
+	ecabal build -w ghc-${GHC_VERSION}
 else
-	ecabal build -w ghc-${GHC_VERSION} -finternal-downloader -ftui
+	ecabal build -w ghc-${GHC_VERSION} -finternal-downloader
 fi
 
 cp "$(ecabal new-exec --enable-tests --verbose=0 --offline sh -- -c 'command -v ghcup')" .

3rdparty/libarchive/c/autoconf-linux/config.h

@@ -260,7 +260,7 @@
 /* #undef HAVE_ACL_IS_TRIVIAL_NP */
 
 /* Define to 1 if you have the <acl/libacl.h> header file. */
-/* #undef HAVE_ACL_LIBACL_H */
+#define HAVE_ACL_LIBACL_H 1
 
 /* Define to 1 if the system has the type `acl_permset_t'. */
 /* #undef HAVE_ACL_PERMSET_T */
@@ -453,7 +453,6 @@
 /* #undef HAVE_EXPAT_H */
 
 /* Define to 1 if you have the <ext2fs/ext2_fs.h> header file. */
-/* #undef HAVE_EXT2FS_EXT2_FS_H */
 
 /* Define to 1 if you have the `extattr_get_fd' function. */
 /* #undef HAVE_EXTATTR_GET_FD */
@@ -606,7 +605,7 @@
 /* #undef HAVE_LCHFLAGS */
 
 /* Define to 1 if you have the `lchmod' function. */
-/* #undef HAVE_LCHMOD 1 */
+/* #undef HAVE_LCHMOD */
 
 /* Define to 1 if you have the `lchown' function. */
 #define HAVE_LCHOWN 1
@@ -1028,10 +1027,10 @@
 /* #undef HAVE_STRUCT_STAT_ST_UMTIME */
 
 /* Define to 1 if `tm_gmtoff' is a member of `struct tm'. */
-/* #undef HAVE_STRUCT_TM_TM_GMTOFF 1 */
+#define HAVE_STRUCT_TM_TM_GMTOFF 1
 
 /* Define to 1 if `__tm_gmtoff' is a member of `struct tm'. */
-/* #undef HAVE_STRUCT_TM___TM_GMTOFF 1 */
+/* #undef HAVE_STRUCT_TM___TM_GMTOFF */
 
 /* Define to 1 if the system has the type `struct vfsconf'. */
 /* #undef HAVE_STRUCT_VFSCONF */
@@ -1043,10 +1042,9 @@
 #define HAVE_SYMLINK 1
 
 /* Define to 1 if you have the <sys/acl.h> header file. */
-/* #undef HAVE_SYS_ACL_H */
 
 /* Define to 1 if you have the <sys/cdefs.h> header file. */
-/* #undef HAVE_SYS_CDEFS_H */
+#define HAVE_SYS_CDEFS_H 1
 
 /* Define to 1 if you have the <sys/dir.h> header file, and it defines `DIR'.
    */
@@ -1204,7 +1202,7 @@
 #define HAVE_WMEMMOVE 1
 
 /* Define to 1 if you have a working EXT2_IOC_GETFLAGS */
-/* #undef HAVE_WORKING_EXT2_IOC_GETFLAGS */
+#define HAVE_WORKING_EXT2_IOC_GETFLAGS 1
 
 /* Define to 1 if you have a working FS_IOC_GETFLAGS */
 #define HAVE_WORKING_FS_IOC_GETFLAGS 1
@@ -1291,7 +1289,7 @@
 #define STDC_HEADERS 1
 
 /* Define to 1 if strerror_r returns char *. */
-/* #undef STRERROR_R_CHAR_P */
+#define STRERROR_R_CHAR_P 1
 
 /* Define to 1 if you can safely include both <sys/time.h> and <time.h>. */
 #define TIME_WITH_SYS_TIME 1

README.md

@@ -40,13 +40,7 @@ export PATH="$HOME/.cabal/bin:$HOME/.ghcup/bin:$PATH"
 
 See `ghcup --help`.
 
-For the simple interactive TUI, run:
+Common use cases are:
-
-```sh
-ghcup tui
-```
-
-For the full functionality via cli:
 
 ```sh
 # list available ghc/cabal versions

app/ghcup/BrickMain.hs

@@ -1,320 +0,0 @@
-{-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE QuasiQuotes       #-}
-{-# LANGUAGE TypeApplications  #-}
-{-# LANGUAGE TemplateHaskell   #-}
-{-# LANGUAGE OverloadedStrings #-}
-
-module BrickMain where
-
-import           GHCup
-import           GHCup.Download
-import           GHCup.Errors
-import           GHCup.Types
-import           GHCup.Utils
-import           GHCup.Utils.File
-import           GHCup.Utils.Logger
-
-import           Brick
-import           Brick.Widgets.Border
-import           Brick.Widgets.Border.Style
-import           Brick.Widgets.Center
-import           Brick.Widgets.List
-import           Codec.Archive
-import           Control.Exception.Safe
-import           Control.Monad.Logger
-import           Control.Monad.Reader
-import           Control.Monad.Trans.Resource
-import           Data.Bool
-import           Data.Functor
-import           Data.List
-import           Data.Maybe
-import           Data.Char
-import           Data.IORef
-import           Data.String.Interpolate
-import           Data.Vector                    ( Vector )
-import           Data.Versions           hiding ( str )
-import           Haskus.Utils.Variant.Excepts
-import           Prelude                 hiding ( appendFile )
-import           System.Exit
-import           System.IO.Unsafe
-import           URI.ByteString
-
-import qualified Data.Text                     as T
-import qualified Graphics.Vty                  as Vty
-import qualified Data.Vector                   as V
-
-
-data AppState = AppState {
-    lr :: LR
-  , dls :: GHCupDownloads
-}
-
-type LR = GenericList String Vector ListResult
-
-
-keyHandlers :: [(Char, String, AppState -> EventM n (Next AppState))]
-keyHandlers =
-  [ ('q', "Quit"     , halt)
-  , ('i', "Install"  , withIOAction install')
-  , ('u', "Uninstall", withIOAction del')
-  , ('s', "Set"      , withIOAction set')
-  , ('c', "ChangeLog", withIOAction changelog')
-  ]
-
-
-ui :: AppState -> Widget String
-ui AppState {..} =
-  ( padBottom Max
-    $ ( withBorderStyle unicode
-      $ borderWithLabel (str "GHCup")
-      $ (center $ renderList renderItem True lr)
-      )
-    )
-    <=> ( withAttr "help"
-        . txtWrap
-        . T.pack
-        . foldr1 (\x y -> x <> "  " <> y)
-        . (++ ["↑↓:Navigation"])
-        $ (fmap (\(c, s, _) -> (c : ':' : s)) keyHandlers)
-        )
-
- where
-  renderItem b ListResult {..} =
-    let marks = if
-          | lSet       -> (withAttr "set" $ str "✔✔")
-          | lInstalled -> (withAttr "installed" $ str "✓ ")
-          | otherwise  -> (withAttr "not-installed" $ str "✗ ")
-        ver = case lCross of
-          Nothing -> T.unpack . prettyVer $ lVer
-          Just c  -> T.unpack (c <> "-" <> prettyVer lVer)
-    in  (   marks
-        <+> ( padLeft (Pad 2)
-            $ minHSize 20
-            $ (withAttr
-                (bool "inactive" "active" b)
-                (str $ (fmap toLower . show $ lTool) <> " " <> ver)
-              )
-            )
-        <+> (padLeft (Pad 1) $ if null lTag
-              then emptyWidget
-              else
-                foldr1 (\x y -> x <+> str "," <+> y)
-                  $ (fmap printTag $ sort lTag)
-            )
-        )
-
-  printTag Recommended        = withAttr "recommended" $ str "recommended"
-  printTag Latest             = withAttr "latest" $ str "latest"
-  printTag (Base       pvp'') = str ("base-" ++ T.unpack (prettyPVP pvp''))
-  printTag (UnknownTag t    ) = str t
-
-
-minHSize :: Int -> Widget n -> Widget n
-minHSize s' = hLimit s' . vLimit 1 . (<+> fill ' ')
-
-
-app :: App AppState e String
-app = App { appDraw         = \st -> [ui st]
-          , appHandleEvent  = eventHandler
-          , appStartEvent   = return
-          , appAttrMap      = const theMap
-          , appChooseCursor = neverShowCursor
-          }
- where
-  theMap = attrMap
-    Vty.defAttr
-    [ ("active"       , bg Vty.blue)
-    , ("not-installed", fg Vty.red)
-    , ("set"          , fg Vty.green)
-    , ("installed"    , fg Vty.green)
-    , ("recommended"  , fg Vty.green)
-    , ("latest"       , fg Vty.yellow)
-    , ("help"         , Vty.defAttr `Vty.withStyle` Vty.italic)
-    ]
-
-
-eventHandler :: AppState -> BrickEvent n e -> EventM n (Next AppState)
-eventHandler st (VtyEvent (Vty.EvResize _               _)) = continue st
-eventHandler st (VtyEvent (Vty.EvKey    (Vty.KChar 'q') _)) = halt st
-eventHandler st (VtyEvent (Vty.EvKey    Vty.KEsc        _)) = halt st
-eventHandler AppState {..} (VtyEvent (Vty.EvKey (Vty.KUp) _)) =
-  continue (AppState (listMoveUp lr) dls)
-eventHandler AppState {..} (VtyEvent (Vty.EvKey (Vty.KDown) _)) =
-  continue (AppState (listMoveDown lr) dls)
-eventHandler as (VtyEvent (Vty.EvKey (Vty.KChar c) _)) =
-  case find (\(c', _, _) -> c' == c) keyHandlers of
-    Nothing              -> continue as
-    Just (_, _, handler) -> handler as
-eventHandler st _ = continue st
-
-
--- | Suspend the current UI and run an IO action in terminal. If the
--- IO action returns a Left value, then it's thrown as userError.
-withIOAction :: (AppState -> (Int, ListResult) -> IO (Either String a))
-             -> AppState
-             -> EventM n (Next AppState)
-withIOAction action as = case listSelectedElement (lr as) of
-  Nothing      -> continue as
-  Just (ix, e) -> suspendAndResume $ do
-    r <- action as (ix, e)
-    case r of
-      Left  err -> throwIO $ userError err
-      Right _   -> do
-        apps <- (fmap . fmap)
-          (\AppState {..} -> AppState { lr = listMoveTo ix lr, .. })
-          getAppState
-        case apps of
-          Right nas -> do
-            putStrLn "Press enter to continue"
-            _ <- getLine
-            pure nas
-          Left err -> throwIO $ userError err
-
-
-install' :: AppState -> (Int, ListResult) -> IO (Either String ())
-install' AppState {..} (_, ListResult {..}) = do
-  settings <- readIORef settings'
-  l        <- readIORef logger'
-  let runLogger = myLoggerT l
-
-  let
-    run =
-      runLogger
-        . flip runReaderT settings
-        . runResourceT
-        . runE
-          @'[AlreadyInstalled, UnknownArchive, ArchiveResult, DistroNotFound, FileDoesNotExistError, CopyError, NoCompatibleArch, NoDownload, NotInstalled, NoCompatiblePlatform, BuildFailed, TagNotFound, DigestError, DownloadFailed, NoUpdate]
-
-  (run $ do
-      case lTool of
-        GHC   -> liftE $ installGHCBin dls lVer Nothing
-        Cabal -> liftE $ installCabalBin dls lVer Nothing
-        GHCup -> liftE $ upgradeGHCup dls Nothing False $> ()
-    )
-    >>= \case
-          VRight _                          -> pure $ Right ()
-          VLeft  (V (AlreadyInstalled _ _)) -> pure $ Right ()
-          VLeft (V (BuildFailed _ e)) ->
-            pure $ Left [i|Build failed with #{e}|]
-          VLeft (V NoDownload) ->
-            pure $ Left [i|No available version for #{prettyVer lVer}|]
-          VLeft (V NoUpdate) -> pure $ Right ()
-          VLeft e -> pure $ Left [i|#{e}
-Also check the logs in ~/.ghcup/logs|]
-
-
-set' :: AppState -> (Int, ListResult) -> IO (Either String ())
-set' _ (_, ListResult {..}) = do
-  settings <- readIORef settings'
-  l        <- readIORef logger'
-  let runLogger = myLoggerT l
-
-  let run =
-        runLogger
-          . flip runReaderT settings
-          . runE @'[FileDoesNotExistError, NotInstalled, TagNotFound]
-
-  (run $ do
-      case lTool of
-        GHC   -> liftE $ setGHC (GHCTargetVersion lCross lVer) SetGHCOnly $> ()
-        Cabal -> liftE $ setCabal lVer $> ()
-        GHCup -> pure ()
-    )
-    >>= \case
-          VRight _ -> pure $ Right ()
-          VLeft  e -> pure $ Left [i|#{e}|]
-
-
-del' :: AppState -> (Int, ListResult) -> IO (Either String ())
-del' _ (_, ListResult {..}) = do
-  settings <- readIORef settings'
-  l        <- readIORef logger'
-  let runLogger = myLoggerT l
-
-  let run = runLogger . flip runReaderT settings . runE @'[NotInstalled]
-
-  (run $ do
-      case lTool of
-        GHC   -> liftE $ rmGHCVer (GHCTargetVersion lCross lVer) $> ()
-        Cabal -> liftE $ rmCabalVer lVer $> ()
-        GHCup -> pure ()
-    )
-    >>= \case
-          VRight _ -> pure $ Right ()
-          VLeft  e -> pure $ Left [i|#{e}|]
-
-
-changelog' :: AppState -> (Int, ListResult) -> IO (Either String ())
-changelog' AppState {..} (_, ListResult {..}) = do
-  case getChangeLog dls lTool (Left lVer) of
-    Nothing -> pure $ Left
-      [i|Could not find ChangeLog for #{lTool}, version #{prettyVer lVer}|]
-    Just uri -> do
-      exec "xdg-open" True [serializeURIRef' uri] Nothing Nothing >>= \case
-        Right _ -> pure $ Right ()
-        Left  e -> pure $ Left [i|#{e}|]
-
-
-settings' :: IORef Settings
-{-# NOINLINE settings' #-}
-settings' = unsafePerformIO
-  (newIORef Settings { cache      = True
-                     , noVerify   = False
-                     , keepDirs   = Never
-                     , downloader = Curl
-                     }
-  )
-
-
-logger' :: IORef LoggerConfig
-{-# NOINLINE logger' #-}
-logger' = unsafePerformIO
-  (newIORef $ LoggerConfig { lcPrintDebug = False
-                           , colorOutter  = \_ -> pure ()
-                           , rawOutter    = \_ -> pure ()
-                           }
-  )
-
-
-brickMain :: Settings -> LoggerConfig -> IO ()
-brickMain s l = do
-  writeIORef settings' s
-  -- logger interpreter
-  writeIORef logger'   l
-  let runLogger = myLoggerT l
-
-  eApps <- getAppState
-  case eApps of
-    Right as -> defaultMain app (selectLatest as) $> ()
-    Left  e  -> do
-      runLogger ($(logError) [i|Error building app state: #{show e}|])
-      exitWith $ ExitFailure 2
- where
-  selectLatest :: AppState -> AppState
-  selectLatest AppState {..} =
-    (\ix -> AppState { lr = listMoveTo ix lr, .. })
-      . fromJust
-      . V.findIndex (\ListResult {..} -> lTool == GHC && Latest `elem` lTag)
-      $ (listElements lr)
-
-
-getAppState :: IO (Either String AppState)
-getAppState = do
-  settings <- readIORef settings'
-  l        <- readIORef logger'
-  let runLogger = myLoggerT l
-
-  r <-
-    runLogger
-    . flip runReaderT settings
-    . runE
-      @'[JSONError, DownloadFailed, FileDoesNotExistError, NoCompatiblePlatform, NoCompatibleArch, DistroNotFound]
-    $ do
-        (GHCupInfo _ dls) <- liftE $ getDownloadsF GHCupURL
-
-        lV                <- liftE $ listVersions dls Nothing Nothing
-        pure $ (AppState (list "Tool versions" (V.fromList lV) 1) dls)
-
-  case r of
-    VRight a -> pure $ Right a
-    VLeft  e -> pure $ Left [i|#{e}|]

app/ghcup/Main.hs

@@ -10,10 +10,6 @@
 
 module Main where
 
-#if defined(BRICK)
-import           BrickMain                    ( brickMain )
-#endif
-
 import           GHCup
 import           GHCup.Download
 import           GHCup.Errors
@@ -99,9 +95,6 @@ data Command
   | Upgrade UpgradeOpts Bool
   | ToolRequirements
   | ChangeLog ChangeLogOptions
-#if defined(BRICK)
-  | Interactive
-#endif
 
 data ToolVersion = ToolVersion GHCTargetVersion -- target is ignored for cabal
                  | ToolTag Tag
@@ -230,20 +223,7 @@ opts =
 com :: Parser Command
 com =
   subparser
-#if defined(BRICK)
       (  command
-          "tui"
-          (   (\_ -> Interactive)
-          <$> (info
-                helper
-                (  progDesc "Start the interactive GHCup UI"
-                )
-              )
-          )
-      <>  command
-#else
-      (  command
-#endif
           "install"
           (   Install
           <$> (info
@@ -890,12 +870,11 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
 
           -- logger interpreter
           logfile <- initGHCupFileLogging [rel|ghcup.log|]
-          let loggerConfig = LoggerConfig
+          let runLogger = myLoggerT LoggerConfig
                 { lcPrintDebug = optVerbose
                 , colorOutter  = B.hPut stderr
                 , rawOutter    = appendFile logfile
                 }
-          let runLogger = myLoggerT loggerConfig
 
 
           -------------------------
@@ -931,6 +910,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                   @'[ FileDoesNotExistError
                     , NotInstalled
                     , TagNotFound
+                    , TagNotFound
                     ]
 
           let
@@ -943,7 +923,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
 
           let runListGHC = runLogger . runE @'[NoCompatiblePlatform, NoCompatibleArch, DistroNotFound]
 
-          let runRm =
+          let runRmGHC =
                 runLogger . flip runReaderT settings . runE @'[NotInstalled]
 
           let runDebugInfo =
@@ -1127,7 +1107,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                           pure $ ExitFailure 14
 
           let rmGHC' RmOptions{..} =
-                (runRm $ do
+                (runRmGHC $ do
                     liftE $ rmGHCVer ghcVer
                   )
                   >>= \case
@@ -1137,7 +1117,7 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
                           pure $ ExitFailure 7
 
           let rmCabal' tv =
-                (runRm $ do
+                (runSetCabal $ do
                     liftE $ rmCabalVer tv
                   )
                   >>= \case
@@ -1149,9 +1129,6 @@ Report bugs at <https://gitlab.haskell.org/haskell/ghcup-hs/issues>|]
 
 
           res <- case optCommand of
-#if defined(BRICK)
-            Interactive -> liftIO $ brickMain settings loggerConfig >> pure ExitSuccess
-#endif
             Install (Right iopts) -> do
               runLogger ($(logWarn) [i|This is an old-style command for installing GHC. Use 'ghcup install ghc' instead.|])
               installGHC iopts

ghcup.cabal

@@ -21,11 +21,6 @@ source-repository head
   type:     git
   location: https://gitlab.haskell.org/haskell/ghcup-hs.git
 
-flag tui
-  description: Build the brick powered tui (ghcup tui)
-  default:     False
-  manual:      True
-
 flag internal-downloader
   description: Compile the internal downloader, which links against OpenSSL
   default:     False
@@ -55,9 +50,6 @@ common base16-bytestring
 common binary
   build-depends: binary >=0.8.6.0
 
-common brick
-  build-depends: brick >=0.54
-
 common bytestring
   build-depends: bytestring >=0.10
 
@@ -166,6 +158,7 @@ common string-interpolate
 common table-layout
   build-depends: table-layout >=0.8
 
+
 common template-haskell
   build-depends: template-haskell >=2.7
 
@@ -205,9 +198,6 @@ common vector
 common versions
   build-depends: versions >=3.5
 
-common vty
-  build-depends: vty >=5.28.2
-
 common word8
   build-depends: word8 >=0.1.3
 
@@ -360,13 +350,6 @@ executable ghcup
   if flag(internal-downloader)
     cpp-options:     -DINTERNAL_DOWNLOADER
 
-  if flag(tui)
-    import:
-      brick
-      , vector
-      , vty
-    other-modules: BrickMain
-    cpp-options:     -DBRICK
 
 executable ghcup-gen
   import:

lib/GHCup.hs

@@ -927,13 +927,20 @@ upgradeGHCup dls mtarget force = do
           `unionFileModes` ownerExecuteMode
           `unionFileModes` groupExecuteMode
           `unionFileModes` otherExecuteMode
-  binDir <- liftIO $ ghcupBinDir
+  case mtarget of
-  let fullDest = fromMaybe (binDir </> fn) mtarget
+    Nothing -> do
-  liftIO $ hideError NoSuchThing $ deleteFile fullDest
+      dest <- liftIO $ ghcupBinDir
-  handleIO (throwE . CopyError . show) $ liftIO $ copyFile p
+      liftIO $ hideError NoSuchThing $ deleteFile (dest </> fn)
-                                                           fullDest
+      handleIO (throwE . CopyError . show) $ liftIO $ copyFile p
-                                                           Overwrite
+                                                               (dest </> fn)
-  liftIO $ setFileMode (toFilePath fullDest) fileMode'
+                                                               Overwrite
+      liftIO $ setFileMode (toFilePath (dest </> fn)) fileMode'
+    Just fullDest -> do
+      liftIO $ hideError NoSuchThing $ deleteFile fullDest
+      handleIO (throwE . CopyError . show) $ liftIO $ copyFile p
+                                                               fullDest
+                                                               Overwrite
+      liftIO $ setFileMode (toFilePath fullDest) fileMode'
   pure latestVer
 
 

www/ghcup.css

@@ -101,6 +101,7 @@ body#idx p.other-help {
 
 .instructions div.command-button {
 	display: flex;
+	align-items: center;
 }
 
 .instructions div.command-button button {
@@ -111,7 +112,7 @@ body#idx p.other-help {
 	border-style: solid;
 	border-radius: 3px;
 
-    margin-left: 1rem;
+    margin-left: 0.5rem;
     margin-right: auto;
 	margin-top: 25px;
 	margin-bottom: 25px;
@@ -134,20 +135,21 @@ hr {
 #platform-instructions-linux > div > pre,
 #platform-instructions-mac > div > pre,
 #platform-instructions-freebsd > div > pre,
-#platform-instructions-win32 > pre,
+#platform-instructions-win32 > div > pre,
-#platform-instructions-win64 > pre,
+#platform-instructions-win64 > div > pre,
 #platform-instructions-default > div > div > pre,
 #platform-instructions-unknown > div > div > pre {
     background-color: #515151;
     color: white;
     margin-left: auto;
-    margin-right: auto;
     padding-top: 1rem;
     padding-bottom: 1rem;
     padding-right: 1rem;
     text-align: center;
     border-radius: 3px;
     box-shadow: inset 0px 0px 20px 0px #333333;
+	font-size: 0.6em;
+	width: 40rem;
 }
 
 #platform-instructions-win32 a.windows-download,

www/index.html

@@ -46,6 +46,9 @@
         <p>
           To install Haskell, follow the instructions on
           <a class="windows-download" href="https://www.haskell.org/platform/#windows">Haskell Platform</a>
+		<p>If you're a Windows Subsystem for Linux user run the following in your terminal, then follow the onscreen instructions to install Haskell.
+		</p>
+		<div class="command-button"><pre><span class='ghcup-command'>curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh</span></pre><button class="tooltip" onclick="copyToClipboard()"><img src="copy.svg" alt="" /><span class="tooltiptext">Copy to clipboard</span></button></div>
         </p>
         <p class="other-help">You appear to be running Windows 32-bit. If not, <a class="default-platform-button" href="#">display all supported installers</a>.</p>
       </div>
@@ -55,6 +58,9 @@
           To install Haskell, follow the instructions on
           <a class="windows-download" href="https://www.haskell.org/platform/#windows">Haskell Platform</a>
         </p>
+		<p>If you're a Windows Subsystem for Linux user run the following in your terminal, then follow the onscreen instructions to install Haskell.
+		</p>
+		<div class="command-button"><pre><span class='ghcup-command'>curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh</span></pre><button class="tooltip" onclick="copyToClipboard()"><img src="copy.svg" alt="" /><span class="tooltiptext">Copy to clipboard</span></button></div>
         <p class="other-help">You appear to be running Windows 64-bit. If not, <a class="default-platform-button" href="#">display all supported installers</a>.</p>
       </div>
 
@@ -77,7 +83,7 @@
 
         <!-- duplicate the default cross-platform instructions -->
         <div>
-          <p>If you are running Linux, macOS or FreeBSD,<br/>run the following in your terminal (as a user other than root), then follow the onscreen instructions.</p>
+          <p>If you are running Linux, macOS, FreeBSD or Windows Subsystem for Linux, run the following in your terminal (as a user other than root), then follow the onscreen instructions.</p>
 		  <div class="command-button"><pre><span class='ghcup-command'>curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh</span></pre><button class="tooltip" onclick="copyToClipboard()"><img src="copy.svg" alt="" /><span class="tooltiptext">Copy to clipboard</span></button></div>
           <p class="other-help">If you don't like curl | sh, see <a href="https://gitlab.haskell.org/haskell/ghcup-hs#manual-install">other installation methods</a>.</p>
         </div>
@@ -95,7 +101,7 @@
 
       <div id="platform-instructions-default" class="instructions">
         <div>
-          <p>To install Haskell, if you are running Linux, macOS or FreeBSD,<br/>run the following
+          <p>To install Haskell, if you are running Linux, macOS, FreeBSD or Windows Subsystem for Linux, run the following
           in your terminal (as a user other than root), then follow the onscreen instructions.</p>
 		  <div class="command-button"><pre><span class='ghcup-command'>curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh</span></pre><button class="tooltip" onclick="copyToClipboard()"><img src="copy.svg" alt="" /><span class="tooltiptext">Copy to clipboard</span></button></div>
           <p class="other-help">If you don't like curl | sh, see <a href="https://gitlab.haskell.org/haskell/ghcup-hs#manual-install">other installation methods</a>.</p>
@@ -140,7 +146,7 @@
 
       <div id="platform-instructions-default" class="instructions">
         <div>
-          <p>To install Haskell, if you are running Linux, macOS or FreeBSD,<br/>run the following
+          <p>To install Haskell, if you are running Linux, macOS, FreeBSD or Windows Subsystem for Linux, run the following
           in your terminal (as a user other than root), then follow the onscreen instructions.</p>
 		  <pre><span class='ghcup-command'>curl --proto '=https' --tlsv1.2 -sSf https://get-ghcup.haskell.org | sh</span></pre>
           <p class="other-help">If you don't like curl | sh, see <a href="https://gitlab.haskell.org/haskell/ghcup-hs#manual-install">other installation methods</a>.</p>