Mergify Stack Workflow

First: Does This Repository Use Stacks?

This skill applies only to a repository that uses Mergify stacks. Check before anything else:

mergify stack hooks                                # commit-msg "Wrapper: installed" (or "legacy") → uses stacks
git log -n 20 --format=%B | grep -c '^Change-Id: I'   # any match → uses stacks

• Either check passes: follow this skill. If only the trailers are there (the commit-msg wrapper is not installed in this clone), run mergify stack setup once before committing: the hook is what adds the Change-Id trailer, and mergify stack push refuses a commit without one.
• Neither passes, or mergify is not installed: the repository does not use stacks. Ignore the rest of this skill and use plain git and gh, following the repository's own conventions. Do not run mergify stack setup or suggest it.

Stack Philosophy

A branch is a stack. Keep stacks short and focused:

• A stack should only contain commits that depend on each other
• Rationale: longer stacks take longer to merge