Update git package submodules after clone and reset

For packages identified by git locations, this changes the logic to:
1. clone the repo
2. reset --hard to a specific commit
3. update submodules (recursively)

ChangeLog.md

@@ -90,6 +90,8 @@ Bug fixes:
 * Fix `subdirs` for git repos in `extra-deps` to match whole directory names.
   Also fixes for `subdirs: .`. See
   [#4292](https://github.com/commercialhaskell/stack/issues/4292)
+* Fix for git packages to update submodules to the correct state. See
+  [#4314](https://github.com/commercialhaskell/stack/pull/4314)
 
 
 ## v1.9.0.1 (release candidate)

subs/pantry/src/Pantry/Repo.hs

@@ -71,25 +71,25 @@ getRepo' repo@(Repo url commit repoType' subdir) pm =
         dir = tmpdir </> suffix
         tarball = tmpdir </> "foo.tar"
 
-    let (commandName, cloneArgs, resetArgs, archiveArgs) =
+    let (commandName, resetArgs, submoduleArgs, archiveArgs) =
           case repoType' of
             RepoGit ->
               ( "git"
-              , ["--recursive"]
               , ["reset", "--hard", T.unpack commit]
+              , ["submodule", "update", "--init", "--recursive"]
               , ["archive", "-o", tarball, "HEAD"]
               )
             RepoHg ->
               ( "hg"
-              , []
               , ["update", "-C", T.unpack commit]
+              , []
               , ["archive", tarball, "-X", ".hg_archival.txt"]
               )
 
     logInfo $ "Cloning " <> display commit <> " from " <> display url
     void $ proc
       commandName
-      ("clone" : cloneArgs ++ [T.unpack url, suffix])
+      ("clone" : [T.unpack url, suffix])
       readProcess_
     -- On Windows 10, an upstream issue with the `git clone` command means that
     -- command clears, but does not then restore, the
@@ -101,6 +101,7 @@ getRepo' repo@(Repo url commit repoType' subdir) pm =
 
     withWorkingDir dir $ do
       void $ proc commandName resetArgs readProcess_
+      void $ proc commandName submoduleArgs readProcess_
       void $ proc commandName archiveArgs readProcess_
     abs' <- resolveFile' tarball
     getArchive