Fix commercialhaskell#4778: autorun autoreconf on Windows too

In module `Stack.Setup`, `pacman` is used to add the `perl` and `autoconf` packages to stack's MSYS2.

In module `Stack.Build.Execute`, the code uses command `sh autoreconf -i` for Windows, instead of just `autoreconf -i`.

The implementation involves two hacks:

1. `pacman` and `sh autoreconf -i` seem to clear and not restore ANSI capability on native Windows terminals. A hack restores the ANSI capability (using the same hack that was once used for `git clone` - fix commercialhaskell#4121).
2. MSYS2's current `perl` package (5.28.1-2) is broken. So the `perl` installed by stack is downgraded to 5.28.0-1, which works. This will need to be revisited once `perl` is fixed on MSYS2.

This has been tested on Windows 10 (only) by deleting stack's MSYS2 (so that stack reinstalls it) and by then building the `process` package (which makes use of `configure`) using stack.

src/Stack/Build/Execute.hs

@@ -71,6 +71,7 @@ import           Stack.Config
 import           Stack.Constants
 import           Stack.Constants.Config
 import           Stack.Coverage
+import           Stack.DefaultColorWhen (defaultColorWhen)
 import           Stack.GhcPkg
 import           Stack.Package
 import           Stack.PackageDump
@@ -911,8 +912,15 @@ ensureConfig newConfigCache pkgDir ExecuteEnv {..} announce cabal cabalfp task =
       exists <- doesFileExist fp
       unless exists $ do
         logInfo $ "Trying to generate configure with autoreconf in " <> fromString (toFilePath pkgDir)
-        withWorkingDir (toFilePath pkgDir) $ readProcessNull "autoreconf" ["-i"] `catchAny` \ex ->
+        let cmd = if osIsWindows then "sh" else "autoreconf"
+            args = if osIsWindows then ["autoreconf", "-i"] else ["-i"]
+        withWorkingDir (toFilePath pkgDir) $ readProcessNull cmd args `catchAny` \ex ->
           logWarn $ "Unable to run autoreconf: " <> displayShow ex
+    -- On Windows 10, an upstream issue with the `sh autoreconf -i` command
+    -- means that command clears, but does not then restore, the
+    -- ENABLE_VIRTUAL_TERMINAL_PROCESSING flag for native terminals. The
+    -- folowing hack re-enables the lost ANSI-capability.
+        when osIsWindows (void $ liftIO defaultColorWhen)
 
 -- | Make a padded prefix for log messages
 packageNamePrefix :: ExecuteEnv -> PackageName -> Utf8Builder

src/Stack/Setup.hs

@@ -77,6 +77,7 @@ import              Stack.Build.Source (loadSourceMap, hashSourceMapData)
 import              Stack.Build.Target (NeedTargets(..), parseTargets)
 import              Stack.Constants
 import              Stack.Constants.Config (distRelativeDir)
+import              Stack.DefaultColorWhen (defaultColorWhen)
 import              Stack.GhcPkg (createDatabase, getGlobalDB, mkGhcPackagePath, ghcPkgPathEnvVar)
 import              Stack.Prelude hiding (Display (..))
 import              Stack.SourceMap
@@ -1483,6 +1484,28 @@ installMsys2Windows osKey si archiveFile archiveType _tempDir destDir = do
     menv <- mkProcessContext newEnv
     withWorkingDir (toFilePath destDir) $ withProcessContext menv
       $ proc "sh" ["--login", "-c", "true"] runProcess_
+    -- Install MSYS2 package perl. Used by the autoreconf shell script file.
+    -- perl 5.28.1-2 is broken (see
+    -- https://github.com/msys2/MSYS2-packages/issues/1611). perl 5.28.0-1
+    -- works, so downgrading to that version, in the alternative.
+    withWorkingDir (toFilePath destDir) $ withProcessContext menv
+    --  $ proc "pacman" ["-Sy", "--noconfirm", "perl"] runProcess_
+      $ proc
+          "pacman"
+          [ "-U"
+          , "--noconfirm"
+          , "http://repo.msys2.org/msys/x86_64/perl-5.28.0-1-x86_64.pkg.tar.xz"
+          ]
+        runProcess_
+    -- Install MSYS2 package autoconf. Provides the autoreconf shell script
+    -- file.
+    withWorkingDir (toFilePath destDir) $ withProcessContext menv
+      $ proc "pacman" ["-Sy", "--noconfirm", "autoconf"] runProcess_
+    -- On Windows 10, an upstream issue with the `pacman` command means that
+    -- command clears, but does not then restore, the
+    -- ENABLE_VIRTUAL_TERMINAL_PROCESSING flag for native terminals. The
+    -- folowing hack re-enables the lost ANSI-capability.
+    void $ liftIO defaultColorWhen
 
     -- No longer installing git, it's unreliable
     -- (https://github.com/commercialhaskell/stack/issues/1046) and the