nikivdev/code · error

git fetch {} --prune failed: {}

Error message

git fetch {} --prune failed: {}

What it means

Thrown in src/sync.rs when a plain `git fetch <remote> --prune` fails during the sync remote-fetch stage. The stderr is checked first: a 'case-insensitive filesystem' warning is tolerated, but any other failure bails with the remote name and trimmed stderr. Fetches update remote-tracking refs and prune deleted ones.

Source

Thrown at src/sync.rs:3965

) -> Result<()> {
    let before_tip = remote_branch_tip(repo_root, remote, remote_branch);

    match fetch_mode {
        SyncRemoteFetchMode::FullRemote => {
            let fetch = Command::new("git")
                .current_dir(repo_root)
                .args(["fetch", remote, "--prune"])
                .output()
                .with_context(|| format!("failed to run git fetch {}", remote))?;
            if !fetch.status.success() {
                let stderr = String::from_utf8_lossy(&fetch.stderr);
                if stderr.contains("case-insensitive filesystem") {
                    sync_stderrln!(
                        "  Warning: {} has refs that differ only in case; fetch continued anyway",
                        remote
                    );
                } else {
                    bail!("git fetch {} --prune failed: {}", remote, stderr.trim());
                }
            }
            recorder.record(stage, format!("fetched {}", remote));
        }
        SyncRemoteFetchMode::SingleBranch => {
            let refspec = format!(
                "+refs/heads/{}:refs/remotes/{}/{}",
                remote_branch, remote, remote_branch
            );
            git_run_in(repo_root, &["fetch", remote, "--prune", &refspec])?;
            recorder.record(stage, format!("fetched {} {}", remote, remote_branch));
        }
    }

    if remote == "upstream" {
        let local_upstream_exists =
            git_capture_in(repo_root, &["rev-parse", "--verify", "refs/heads/upstream"]).is_ok();
        if local_upstream_exists {

View on GitHub (pinned to a747e741ae)

Solutions

  1. Read the stderr embedded in the message for the concrete cause and address it (auth, network, or remote URL).
  2. Test connectivity/auth manually: `git fetch <remote> --prune` in the repo to reproduce outside the tool.
  3. Fix credentials: load the SSH key into the agent or refresh the HTTPS token in the credential helper.
  4. Verify the remote exists and the URL is current with `git remote -v`; update via `git remote set-url`.

Example fix

// before
f sync
// error: git fetch origin --prune failed: fatal: Authentication failed

// after (fix auth, then retry)
ssh-add ~/.ssh/id_ed25519
git fetch origin --prune   # verify succeeds
f sync
Defensive patterns

Strategy: retry

Validate before calling

git ls-remote "$REMOTE" HEAD >/dev/null 2>&1 || { echo "git fetch $REMOTE will fail: unreachable/auth"; exit 1; }

Try / catch

match sync::run(&repo_root, &cmd) {
    Err(e) if e.to_string().starts_with("git fetch ") && e.to_string().contains("--prune failed") => {
        eprintln!("Fetch failed: {} — check remote auth/connectivity, then retry", e);
    }
    other => other,
}

Prevention

When it happens

Trigger: The SyncRemoteFetchMode::All path runs `git fetch <remote> --prune` and it exits non-zero with stderr that does not mention 'case-insensitive filesystem' — e.g., auth failure, unknown remote, DNS failure, or refspec lock errors.

Common situations: Remote credentials expired or SSH agent lacks the key; remote URL points at a deleted/renamed repo; offline/VPN down; packed-refs permission issues in .git.

Related errors

AI-assisted analysis of nikivdev/code@a747e741ae (2026-09-01). Data as JSON: /api/errors/84e368e994842f84. Report an issue: GitHub.