Fetch already cloned working copies and add test fixture

This adds another version of the same package fetched via git. The same
working copy from _cache/git/<owner>/<repo> is re-used in both
PrepareSource steps (which hopefully do not conflict) and copied onto
individual _cache/<package>/<version> directories.

The second package version in the git-submodule fixture _sources also
uses a tag name as rev to highlight this is possible as well.

app/Foliage/GitClone.hs

@@ -10,7 +10,6 @@ module Foliage.GitClone (
 )
 where
 
-import Control.Monad (unless)
 import Development.Shake
 import Development.Shake.Classes
 import Development.Shake.FilePath
@@ -46,9 +45,11 @@ addGitCloneRule cacheDir = addBuiltinRule noLint noIdentity run
     let path = cacheDir </> "git" </> show repo
 
     alreadyCloned <- doesDirectoryExist path
-    unless alreadyCloned $ do
-      let url = "https://github.com/" <> show repo <> ".git"
-      command_ [] "git" ["clone", "--recursive", url, path]
+    if alreadyCloned
+      then command_ [Cwd path] "git" ["fetch"]
+      else do
+        let url = "https://github.com/" <> show repo <> ".git"
+        command_ [] "git" ["clone", "--recursive", url, path]
 
     command_ [Cwd path] "git" ["checkout", show rev]
     command_ [Cwd path] "git" ["submodule", "update"]

tests/Tests.hs

@@ -35,7 +35,8 @@ main = do
                   assertFailure "entry for pkg-a-2.3.4.5 is missing"
                 Just entry -> do
                   entryTime entry @?= 1648534790
-      , testCaseSteps "git submodules" $ \step ->
+      , ---
+        testCaseSteps "git submodules" $ \step ->
           inTemporaryDirectoryWithFixture "tests/fixtures/git-submodule" $ do
             step "Building repository"
             callCommand "foliage build"

tests/fixtures/git-submodule/_sources/foliage-test-with-submodule/1.0.0/meta.toml

@@ -1,2 +1,2 @@
-timestamp = 2023-11-03T15:53:59+00:00
+timestamp = 2023-11-03T17:35:22+00:00
 github = { repo = "cardano-scaling/foliage-test-with-submodule", rev = "db5874494ee5bac3fa8fee07d5806fcec27a2f4e" }

tests/fixtures/git-submodule/_sources/foliage-test-with-submodule/1.1.0/meta.toml

@@ -0,0 +1,2 @@
+timestamp = 2023-11-03T15:53:59+00:00
+github = { repo = "cardano-scaling/foliage-test-with-submodule", rev = "1.1.0" }