gitbutlerapp/gitbutler · error · anyhow::Error

Unsupported rev-spec for revision log: {other}

Error message

Unsupported rev-spec for revision log: {other}

What it means

`but revision log` parses the rev-spec with gix and only handles two `Spec` outcomes: `Include` (single commit) and `Range` (`a..b`). Any other parsed form — e.g. `Spec::Exclude` from `..b`-style specs or other plumbing spec variants — hits this bail, printing the spec kind. The spec parsed successfully; it's the shape that's unsupported.

Source

Thrown at crates/but-debug/src/command/revision.rs:48

        }
    }
}

fn log(
    repo: &gix::Repository,
    meta: &EmptyRefMetadata,
    log_args: &LogArgs,
    out: &mut dyn io::Write,
) -> Result<()> {
    let parsed = repo
        .rev_parse(log_args.rev_spec.as_str())
        .with_context(|| format!("Failed to parse rev-spec '{}'", log_args.rev_spec))?
        .detach();

    let (included, excluded) = match parsed {
        Spec::Include(commit_id) => (commit_id, None),
        Spec::Range { from, to } => (to, Some(from)),
        other => bail!("Unsupported rev-spec for revision log: {other}"),
    };
    let mut graph_commits = vec![included];
    graph_commits.extend(excluded);

    let graph_tips = args_to_tips(repo, &log_args.graph)?;
    let graph = {
        let _span =
            tracing::info_span!("build graph", commit_count = graph_commits.len()).entered();
        graph_for_revisions(repo, meta, &graph_commits, graph_tips)?
    };

    let _span = tracing::info_span!("traverse graph").entered();
    let commits = if let Some(excluded) = excluded {
        graph.find_commit_ids_reachable_from_a_not_b(
            included,
            excluded,
            FirstParent::from(log_args.first_parent),
        )?

View on GitHub (pinned to caf1f223d3)

Solutions

1. Use an explicit range: `but revision log a..b`.
2. Use a single include spec `but revision log <rev>` — but note this command additionally requires a range for the exclusion step, so prefer `a..b`.
3. Check the printed `{other}` variant to see which spec shape you produced and rewrite the spec into `a..b` form.

Example fix

# before
but revision log ..feature-x

# after
but revision log main..feature-x

# Shell — accept only forms this command supports
spec="$1"
case "$spec" in
  *..*) ;;                # a..b style is fine
  *) echo "use a..b form" >&2; exit 2 ;;
esac
but revision log "$spec"

When it happens

Trigger: Passing a rev-spec that gix parses into a non-Include/non-Range spec, such as an exclude-only spec (`..branch`), since `revision log` only knows how to drive inclusion plus at most one exclusion.

Common situations: Muscle-memory git log syntax (`git log ..next`, `^ref` forms) carried over to `but revision log`; scripts reusing rev-specs from other git commands.

Related errors

• Need to specify a rev-spec of form `a..b` to indicate an exc
• BUG: It should not be possible to omit sources
• {} target value is required
• target kind is required when target value is provided
• Invalid source: expected an uncommitted file or branch

AI-assisted analysis of gitbutlerapp/gitbutler@caf1f223d3 (2026-08-20). Data as JSON: /api/errors/31ed63de46fd99e4. Report an issue: GitHub.