What causes "line {line_number}: pick requires exactly one commit" in gitbutlerapp/gitbutler?

Use exactly one commit spec: `pick 4f2a9c1`.

gitbutlerapp/gitbutler · error · anyhow::Error

line {line_number}: pick requires exactly one commit

Error message

line {line_number}: pick requires exactly one commit

What it means

Raised by `parse_integration_steps_script` when a `pick` line does not have exactly one argument. Tokens are whitespace-split from the command part (before any `|`), so pick must be `pick <commit-spec>` with exactly one spec.

Source

Thrown at crates/but-workspace/src/branch/integrate_branch_upstream/parsing.rs:48

        if trimmed.is_empty() || trimmed.starts_with('#') {
            continue;
        }

        let (command_part, message_part) = split_message_clause(trimmed)
            .with_context(|| format!("line {line_number}: invalid message clause"))?;
        let tokens = command_part.split_whitespace().collect::<Vec<_>>();
        let Some(command) = tokens.first().copied() else {
            continue;
        };
        let arguments = tokens.get(1..).unwrap_or_default();

        let step = match command {
            "pick" => {
                if message_part.is_some() {
                    bail!("line {line_number}: pick does not accept a message clause");
                }
                if arguments.len() != 1 {
                    bail!("line {line_number}: pick requires exactly one commit");
                }
                let commit = arguments
                    .first()
                    .copied()
                    .expect("validated pick arity above");
                InteractiveIntegrationStep::Pick {
                    commit_id: resolve_commit(commit, &allowed_commits).map_err(|err| {
                        anyhow::anyhow!("line {line_number}: invalid pick commit: {err}")
                    })?,
                }
            }
            "merge" => {
                if message_part.is_some() {
                    bail!("line {line_number}: merge does not accept a message clause");
                }
                if arguments.len() != 1 {
                    bail!("line {line_number}: merge requires exactly one commit");
                }

View on GitHub (pinned to caf1f223d3)

Solutions

Use exactly one commit spec: `pick 4f2a9c1`.
If pasting from `git rebase -i`, strip trailing subject text from each line first.
Use a `squash` line if you actually wanted multiple commits combined.

Example fix

# before
pick 4f2a9c1 add login handler

# after
pick 4f2a9c1

Defensive patterns

Strategy: validation

Validate before calling

// Strip git-rebase-style subjects before parsing a pasted todo:
let cleaned: Vec<String> = script.lines().map(|l| {
    let mut it = l.split_whitespace();
    match it.next() {
        Some(cmd @ ("pick" | "merge")) => format!("{} {}", cmd, it.next().unwrap_or_default()),
        _ => l.to_string(),
    }
}).collect();

Try / catch

if let Err(err) = parse_integration_steps_script(&script, &divergence) {
    // err contains 'line {n}: pick requires exactly one commit'; map line n back to the editor
}

Prevention

Validate the script with parse_integration_steps_script before applying.
When pre-filling the editor, always emit bare `pick <sha>` lines (no commit subjects).

When it happens

Trigger: Lines like `pick` (no commit), `pick 4f2a 991b` (two commits), or `pick <full-sha> extra-text`. Note the legacy git-rebase habit `pick <sha> <commit-subject>` fails here because the subject words count as extra arguments.

Common situations: Pasting a git-rebase todo (which appends commit subjects after the SHA) into the integration editor; scripts edited by hand or generated by another tool that emit subjects.

Related errors

AI-assisted analysis of gitbutlerapp/gitbutler@caf1f223d3 (2026-08-20). Data as JSON: /api/errors/df0fa0d89af974cf. Report an issue: GitHub.