Perform clone and checkout in separate steps

src/on_disk_cache.rs

@@ -190,9 +190,12 @@ impl Cache {
                 command
             } else {
                 let mut command = Command::new("git");
+                // smoelius: The checkout is performed as a separate step so that errors that occur
+                // in it can be ignored.
                 command.args([
                     "clone",
                     "--depth=1",
+                    "--no-checkout",
                     "--quiet",
                     url.as_str(),
                     &repo_dir.to_string_lossy(),
@@ -209,6 +212,8 @@ impl Cache {
             let output = command
                 .output()
                 .with_context(|| format!("failed to run command: {command:?}"))?;
+            // smoelius: Perform checkout. As mentioned above, errors are ignored.
+            checkout(&repo_dir)?;
             if output.status.success() {
                 return Ok((url.as_str().to_owned(), repo_dir));
             }
@@ -395,3 +400,17 @@ fn repository_existence(repo_dir: &Path) -> Result<bool> {
         )
     })
 }
+
+fn checkout(repo_dir: &Path) -> Result<()> {
+    let mut command = Command::new("git");
+    command.args(["checkout", "--quiet"]);
+    command.current_dir(repo_dir);
+    let output = command
+        .output()
+        .with_context(|| format!("failed to run command: {command:?}"))?;
+    if !output.status.success() {
+        let error = String::from_utf8(output.stderr)?;
+        crate::warn!("failed to checkout `{}`: {}", repo_dir.display(), error);
+    }
+    Ok(())
+}