diff --git a/app/Foliage/GitClone.hs b/app/Foliage/GitClone.hs
index c16bcb8..78b5c17 100644
--- a/app/Foliage/GitClone.hs
+++ b/app/Foliage/GitClone.hs
@@ -14,7 +14,7 @@ import Development.Shake hiding (doesDirectoryExist)
 import Development.Shake.Classes
 import Development.Shake.FilePath
 import Development.Shake.Rule
-import Foliage.Meta (GitHubRepo)
+import Foliage.Meta (GitHubRepo, gitHubRepoToString)
 import GHC.Generics (Generic)
 import System.Directory (doesDirectoryExist)
 
@@ -23,7 +23,7 @@ newtype GitClone = GitClone {repo :: GitHubRepo}
   deriving newtype (NFData)
 
 instance Show GitClone where
-  show GitClone{repo} = "gitClone " <> show repo
+  show GitClone{repo} = "gitClone " <> gitHubRepoToString repo
 
 instance Hashable GitClone
 
@@ -44,13 +44,13 @@ addGitCloneRule cacheDir = addBuiltinRule noLint noIdentity run
  where
   run :: BuiltinRun GitClone FilePath
   run GitClone{repo} _old _mode = do
-    let path = cacheDir </> "git" </> show repo
+    let path = cacheDir </> "git" </> gitHubRepoToString repo
 
     alreadyCloned <- liftIO $ doesDirectoryExist path
     if alreadyCloned
       then command_ [Cwd path] "git" ["fetch"]
       else do
-        let url = "https://github.com/" <> show repo <> ".git"
+        let url = "https://github.com/" <> gitHubRepoToString repo <> ".git"
         command_ [] "git" ["clone", "--recursive", url, path]
 
     return $ RunResult{runChanged = ChangedRecomputeDiff, runStore = "", runValue = path}
diff --git a/app/Foliage/Meta.hs b/app/Foliage/Meta.hs
index abd11af..c83eabb 100644
--- a/app/Foliage/Meta.hs
+++ b/app/Foliage/Meta.hs
@@ -24,7 +24,9 @@ module Foliage.Meta (
   pattern URISource,
   pattern GitHubSource,
   GitHubRepo (..),
+  gitHubRepoToString,
   GitHubRev (..),
+  gitHubRevToString,
   UTCTime,
   latestRevisionNumber,
   packageVersionSourceToUri,
@@ -51,16 +53,18 @@ import Toml (TomlCodec, (.=))
 import Toml qualified
 
 newtype GitHubRepo = GitHubRepo {unGitHubRepo :: Text}
-  deriving (Eq, Binary, Hashable, NFData) via Text
+  deriving (Show, Eq, Binary, Hashable, NFData) via Text
 
-instance Show GitHubRepo where
-  show = T.unpack . unGitHubRepo
+gitHubRepoToString :: GitHubRepo -> String
+gitHubRepoToString =
+  T.unpack . unGitHubRepo
 
 newtype GitHubRev = GitHubRev {unGitHubRev :: Text}
-  deriving (Eq, Binary, Hashable, NFData) via Text
+  deriving (Show, Eq, Binary, Hashable, NFData) via Text
 
-instance Show GitHubRev where
-  show = T.unpack . unGitHubRev
+gitHubRevToString :: GitHubRev -> String
+gitHubRevToString =
+  T.unpack . unGitHubRev
 
 data PackageVersionSource
   = URISource
diff --git a/app/Foliage/PrepareSource.hs b/app/Foliage/PrepareSource.hs
index 0bce371..ea6e707 100644
--- a/app/Foliage/PrepareSource.hs
+++ b/app/Foliage/PrepareSource.hs
@@ -123,7 +123,7 @@ addPrepareSourceRule inputDir cacheDir = addBuiltinRule noLint noIdentity run
 copyGitWorktree :: FilePath -> GitHubRev -> Maybe FilePath -> FilePath -> Action ()
 copyGitWorktree repoDir rev mSubdir outDir = do
   withTempDir $ \tmpDir -> do
-    command_ [Cwd repoDir] "git" ["worktree", "add", tmpDir, show rev]
+    command_ [Cwd repoDir] "git" ["worktree", "add", tmpDir, gitHubRevToString rev]
     command_ [Cwd tmpDir] "git" ["submodule", "update", "--init"]
     let packageDir = maybe tmpDir (tmpDir </>) mSubdir
     copyDirectoryContents packageDir outDir