rust-lang/cargo · error

could not find `base-sha` for `{UPSTREAM_BRANCH}`, pass it i

Error message

could not find `base-sha` for `{UPSTREAM_BRANCH}`, pass it in directly

What it means

xtask-bump-check needs a base commit to diff against. When --base-sha is not provided, it looks for a remote branch named like the upstream branch (e.g. origin/main). If no such remote branch exists in the local git2 repository, it bails telling the user to pass --base-sha directly.

Source

Thrown at crates/xtask-bump-check/src/xtask.rs:276

        Some(sha) => {
            let obj = repo.revparse_single(sha)?;
            obj.peel_to_commit()?
        }
        None => {
            let upstream_branches = repo
                .branches(Some(git2::BranchType::Remote))?
                .filter_map(|r| r.ok())
                .filter(|(b, _)| {
                    b.name()
                        .ok()
                        .flatten()
                        .unwrap_or_default()
                        .ends_with(&format!("/{UPSTREAM_BRANCH}"))
                })
                .map(|(b, _)| b)
                .collect::<Vec<_>>();
            if upstream_branches.is_empty() {
                anyhow::bail!(
                    "could not find `base-sha` for `{UPSTREAM_BRANCH}`, pass it in directly"
                );
            }
            let upstream_ref = upstream_branches[0].get();
            if upstream_branches.len() > 1 {
                let name = upstream_ref.name().expect("name is valid UTF-8");
                let _ = gctx.shell().warn(format!(
                    "multiple `{UPSTREAM_BRANCH}` found, picking {name}"
                ));
            }
            upstream_ref.peel_to_commit()?
        }
    };
    Ok(base_commit)
}

/// Returns `HEAD` of the Git repository if `head-rev` is missing.
fn get_head_commit<'a>(

View on GitHub (pinned to eb98b54bc9)

Solutions

1. Pass --base-sha <commit> explicitly with the merge-base commit hash.
2. Fetch the upstream remote and branch: `git fetch origin main` (or the relevant upstream).
3. Ensure the clone is not shallow, or deepen it: `git fetch --unshallow`.

Example fix

// before
cargo bump-check
// after
cargo bump-check --base-sha $(git merge-base HEAD origin/main)

// Ensure the upstream branch ref is present
let _ = Command::new("git").args(["fetch", "origin", UPSTREAM_BRANCH]).status();
// then run bump-check, or pass --base-sha explicitly

null

null

When it happens

Trigger: Running `cargo bump-check` without --base-sha in a shallow clone, a fresh checkout without the upstream remote fetched, or a repo where the expected upstream branch (UPSTREAM_BRANCH constant) is absent.

Common situations: CI shallow clones (`depth: 1`) that lack the remote branch; local clones missing the 'origin/main' ref; renamed upstream branches; fork workflows where the upstream remote isn't configured.

Related errors

• Detected changes in these crates but no version bump found:
• Could not find typos version in workflow
• The lints documentation is out-of-date. Run `cargo lint-docs
• argument for --color must be auto, always, or never, but fou
• can't checkout from '{}': you are in the offline mode ({offl

AI-assisted analysis of rust-lang/cargo@eb98b54bc9 (2026-08-11). Data as JSON: /api/errors/803d25f9cac94efd. Report an issue: GitHub.