gitbutlerapp/gitbutler · error

Invalid branch_ref_bytes in assignment request for

Error message

Invalid branch_ref_bytes in assignment request for '{}': {err}

What it means

requests_to_assignments converts user-submitted HunkAssignmentRequest entries into resolvable assignments; when a request targets a Branch, its branch_ref_bytes must parse as a gix::refs::FullName. Malformed ref bytes in the request produce this error naming the file path involved.

Solutions

1. Send branch_ref_bytes as a full ref name like refs/heads/my-branch
2. Use gix::refs::FullName::try_from on the client side to validate before submitting
3. Update the calling client/SDK to the current assignment API format

Example fix

// before
HunkAssignmentTarget::Branch { branch_ref_bytes: BString::from("my-branch") }
// after
HunkAssignmentTarget::Branch { branch_ref_bytes: BString::from("refs/heads/my-branch") }

if let HunkAssignmentTarget::Branch { branch_ref_bytes } = &req.target {
    if gix::refs::FullName::try_from(branch_ref_bytes.clone()).is_err() {
        eprintln!("Invalid ref for {} — use refs/heads/<name>", req.path_bytes.to_str_lossy());
        continue;
    }
}

fn valid_branch_target(t: &HunkAssignmentTarget) -> bool {
    match t {
        HunkAssignmentTarget::Branch { branch_ref_bytes } =>
            gix::refs::FullName::try_from(branch_ref_bytes.clone()).is_ok(),
        _ => true,
    }
}

When it happens

Trigger: Calling assign (crates/but-hunk-assignment/src/lib.rs:619) with a HunkAssignmentTarget::Branch whose branch_ref_bytes is not a valid ref name — clients sending raw bytes that lack the refs/... form.

Common situations: SDK/UI clients constructing targets by hand; stale clients from before the bytes-based API; copy-pasted branch names without the refs/heads/ prefix.

Understand the failure class

Background: "invalid id" errors: invalid identifier format — why libraries reject IDs before lookup, and how to fix them — this error's family across 37 libraries.

Related errors

• Can only delete local branches under refs/heads, got
• Expected ' ' to be a remote tracking branch, but was
• target ref ' ' must be a remote tracking branch
• Aborting due to empty branch name
• Branch name ' ' collides with existing branch

AI-assisted analysis of gitbutlerapp/gitbutler@58e5313667 (2026-09-18). Data as JSON: /api/errors/b5d9306f1b634e3d. Report an issue: GitHub.

Appendix: source

Thrown at crates/but-hunk-assignment/src/lib.rs:619

    }
}

fn requests_to_assignments(
    request: Vec<HunkAssignmentRequest>,
    workspace: &but_graph::Workspace,
) -> Result<Vec<HunkAssignment>> {
    let mut assignments = vec![];
    for req in request {
        let HunkAssignmentRequest {
            hunk_header,
            path_bytes,
            target,
        } = req;
        let branch_ref_bytes = match target {
            None => None,
            Some(HunkAssignmentTarget::Branch { branch_ref_bytes }) => Some(
                gix::refs::FullName::try_from(branch_ref_bytes).map_err(|err| {
                    anyhow::anyhow!(
                        "Invalid branch_ref_bytes in assignment request for '{}': {err}",
                        path_bytes.to_str_lossy()
                    )
                })?,
            ),
            Some(HunkAssignmentTarget::Stack { stack_id }) => Some(
                workspace
                    .find_stack_by_id(stack_id)
                    .and_then(|stack| stack.ref_name())
                    .map(|ref_name| ref_name.to_owned())
                    .ok_or_else(|| {
                        anyhow::anyhow!(
                            "Unknown stack_id {stack_id} in assignment request for '{}'",
                            path_bytes.to_str_lossy()
                        )
                    })?,
            ),
        };

View on GitHub (pinned to 58e5313667)