stacked-prs

name	stacked-prs
description	Manage a PR stacked on another unmerged branch, and re-point it onto main after the base merges. Use when the user says "stack this PR", "restack", "re-point the PR base", "rebase onto main after the base merged", or has a PR whose base branch just merged.

Stacked PRs

A stacked PR targets another open branch as its base (gh pr create --base <branch>), so its diff shows only your commits, not the base's.

Restack onto main after the base merges

A merge queue rebases as it merges, so the base's commits land on main with new SHAs — the old base tip is no longer an ancestor of main, and a plain git rebase origin/main would try to replay the base's commits too. Cut at the old base tip with --onto:

git fetch origin
# OLD_BASE = the base branch's tip SHA from when you stacked
git rebase --onto origin/main <OLD_BASE_SHA> <your-branch>
gh pr edit <PR> --base main
git push --force-with-lease

This replays only your commits onto main. Resolve any conflict against main's version (the base may have been tweaked before merging). Verify clean:

git rev-list --count HEAD..origin/main                                   # 0 = not behind
git merge-tree $(git merge-base HEAD origin/main) HEAD origin/main        # no conflict hunks

Right after the base swap GitHub may briefly report the PR DIRTY while it recomputes — re-check; it settles to MERGEABLE/BLOCKED.