What causes "assignments_error.map(|err| serde_error::Error::new(&*err))" in gitbutlerapp/gitbutler?

Inspect the `assignments_error` string on the emitted event for the root cause.

gitbutlerapp/gitbutler · info · serde_error::Error

assignments_error.map(|err| serde_error::Error::new(&*err))

Error message

assignments_error.map(|err| serde_error::Error::new(&*err))

What it means

In `assignments_and_errors`, the anyhow assignment error is mapped into a serializable `serde_error::Error` before being returned to `emit_worktree_changes`, so the UI receives the assignment failure message alongside the (possibly empty) assignment results. The error is intentionally non-fatal: results and error travel together.

Solutions

Inspect the `assignments_error` string on the emitted event for the root cause.
Retry by triggering a status refresh once the conflicting operation completes.
Remove stale assignment rules pointing at deleted branches.
If the workspace database is locked, close other GitButler clients on the same project.

Defensive patterns

Strategy: try-catch

Try / catch

let (assignments, err) = assignments_and_errors(...)?;
if let Some(e) = err {
    tracing::warn!(error = %e, "assignment failed; falling back to unassigned view");
}

Prevention

Avoid concurrent clients on the same project while the watcher runs.
Clean up assignment rules that reference deleted branches.
Trigger a manual status refresh after failed ticks.

When it happens

Trigger: Calling the worktree-changes pipeline when `but_hunk_assignment` fails to compute assignments (e.g. reference resolution failure, database error, conflicting assignment rules), so `assignments_error` is `Some` and gets converted for the event payload.

Common situations: Workspace database locked or mid-migration while the watcher polls; assignment rules referencing deleted branches; concurrent CLI and app operations on the same project corrupting intermediate state.

Related errors

AI-assisted analysis of gitbutlerapp/gitbutler@58e5313667 (2026-09-18). Data as JSON: /api/errors/4fe7aa017457ac7e. Report an issue: GitHub.

Appendix: source

Thrown at crates/gitbutler-watcher/src/handler.rs:264

fn assignments_and_errors(
    db: HunkAssignmentsHandleMut,
    repo: &gix::Repository,
    workspace: &but_graph::Workspace,
    tree_changes: Vec<TreeChange>,
    context_lines: u32,
) -> Result<(Vec<HunkAssignment>, Option<serde_error::Error>)> {
    let (assignments, assignments_error) = {
        but_hunk_assignment::assignments_with_fallback(
            db,
            repo,
            workspace,
            Some(tree_changes),
            context_lines,
        )?
    };
    Ok((
        assignments,
        assignments_error.map(|err| serde_error::Error::new(&*err)),
    ))
}

View on GitHub (pinned to 58e5313667)