Goal

• Given the current PR is one branch in a stack of sequential PRs, propagate changes reviewed in an earlier PR into every PR stacked on top of it
• Preserve full history: merge forward and commit. Never rebase or force-push
• End with every PR in the stack mergeable, with CI green

When to Use This Skill

• Use after a PR in the middle or bottom of a stack was reviewed and changed, and the branches stacked on top of it need those changes
• Do not use this to build a new stack. Use /auto_task.execute_with_stacked_prs instead
• Follow .claude/skills/auto_task.rules.md section "Ask for Clarification Before Executing an Unclear Plan" when a PR's description is unclear. Do not guess and merge blind

Workflow

Discover the Full Stack

• Get the current PR:

  > gh pr view --json number,title,baseRefName,headRefName,url
  

• Walk up from the current PR's baseRefName, following each branch's own PR (gh pr list --head <base> --state all), until reaching the default branch (master). This is the bottom of the stack
• Walk down from the current PR's headRefName, finding the open PR whose baseRefName equals the previous PR's headRefName (gh pr list --base <branch> --state open). This is the top
• Order the PRs from bottom (based on master) to top
• Check whether the bottom PR is behind the default branch:

  > gh pr view <bottom PR> --json mergeable,mergeStateStatus
  

  If mergeable is CONFLICTING (or the branch is just behind), treat the default branch as an implicit PR_0 at the bottom. It needs the same merge-forward treatment as every other pair

Print the Stack

• Print one table with columns #, Branch, PR (#<NUM> — <title>), Base, e.g.:

  +---+--------------------+-----------------------------------------------+--------+
  | # | Branch             | PR                                             | Base   |
  +---+--------------------+-----------------------------------------------+--------+
  | 1 | ..._invoke_tasks   | #1423 -- auto-pick suffix in git_branch_create | master |
  | 2 | ..._invoke_tasks_2 | #1424 -- unit tests for git_*/gh_* tasks       | #1423  |
  +---+--------------------+-----------------------------------------------+--------+
  

Create and Confirm the Propagation Plan

• Create plan-auto_task.restack.md listing, for every consecutive pair (PR_i, PR_i+1), including (master, PR_1) when the bottom PR is behind the default branch:
  • What PR_i changed, from its GH description and git diff <base_i>...<head_i>
  • What must merge into PR_i+1, and which files are likely to conflict (touched by both)
• Wait for the user to confirm this plan before touching any branch

Propagate Changes Down the Stack

• Process pairs bottom-up, one at a time, so each merge includes everything propagated so far. Start with (master, PR_1) when it is in the plan
• For each pair (PR_i, PR_i+1) or (master, PR_1):
  • Read PR_i's description (gh pr view <PR_i> --json body,title) to resolve conflicts by its intent, not blindly
  • Right before merging, git fetch and confirm the local branch tip matches origin/<branch_i+1>. Another process or session can push mid-stack, and merging on a stale copy silently drops those commits

    > git fetch origin <branch_i> <branch_i+1>
    > git checkout <branch_i+1>
    > git reset --hard origin/<branch_i+1>
    > git merge origin/<branch_i>
    

  • Resolve conflicts by hand, favoring the intent of PR_i's change. Do not use git rebase or force-push
  • Follow .claude/skills/coding.rules.md and .claude/skills/testing.rules.md while resolving conflicts in code and tests
  • Commit the merge and run git push. If the push is rejected because origin/<branch_i+1> moved, re-fetch and redo the merge. Do not force-push over it
• Repeat up to the top of the stack

Make Every PR Mergeable

• For every PR in the stack, in order, run /github.get_pr_ready_to_merge to get its CI green
• After propagation, confirm mergeability:

  > gh pr view <NUM> --json mergeable,mergeStateStatus
  

Report Only Failures

• Do not comment on a PR that merged cleanly and passed CI
• If a PR hits an unresolved conflict or a CI failure needing human input, post one comment explaining the problem:

  > gh pr comment <NUM> --body "<what failed and why>"
  

• Also describe the problem to the user directly. Do not leave it only in a PR comment

Conventions

• Follow .claude/skills/auto_task.rules.md for clarification conventions
• Follow .claude/skills/github.get_pr_ready_to_merge/SKILL.md to get each PR's CI green

Constraints

• Never rebase or force-push a branch in the stack. Propagate with merge commits only, to preserve review history
• Never merge any PR. Merging is the user's decision
• Never skip a PR or reorder the propagation. Always go strictly bottom-up
• Never guess the intent of an unclear PR when resolving a conflict. Stop and ask
• Never merge or build on a local branch copy without re-fetching first. A concurrent session or auto-commit/auto-push process can move a branch in the stack while this skill runs

Verification

• The full stack was discovered from master up through the top PR, matching GitHub's actual base chain, and the bottom PR's mergeability against master was checked
• plan-auto_task.restack.md lists every consecutive pair and was confirmed by the user before any branch was touched
• Every merge between stacked branches is a merge commit, not a rebase. No branch was force-pushed
• gh pr view <NUM> --json mergeable reports MERGEABLE for every PR in the stack
• /github.get_pr_ready_to_merge ran on every PR and its CI is green
• A PR comment exists only for PRs that hit a conflict or CI failure needing human input