Pr Babysitter

PR babysitter

GitHub auto-merge holds a PR until readiness is green AND the branch is up-to-date — but it never updates a BEHIND branch itself (allow_update_branch only permits the update; nothing calls it). Every squash-merge re-BEHINDs the PRs queued behind it, so a merge train stalls after the first car unless someone keeps nudging. That someone is this skill. It is the tail of /automerge, not a replacement — it never merges anything itself.

One pass

1. Snapshot the board

gh pr list --state open --json number,title,isDraft,mergeStateStatus,autoMergeRequest,statusCheckRollup

2. Per open non-draft PR, in this order

• CONFLICTING → surface it for the human. Never resolve or force anything.
• BEHIND → gh pr update-branch <N>. If the update errors (usually a conflict with the new base) → surface as CONFLICT.
• No auto-merge enabled (autoMergeRequest == null) → check whether a prior /automerge round left P1 comments with no push since (gh pr view <N> --json comments,commits):
  • P1s still standing → surface, skip. The human fixes; a new push makes it eligible again.
  • Otherwise → run the full automerge skill pipeline on it (classify → exempt-enable or gate-review→refute). This may spawn Opus reviewer/refuter agents — that's the point; classification still fails toward GATE.
• Checks failing (any statusCheckRollup conclusion FAILURE) → surface with the failing check's name. Don't auto-fix, don't re-run blindly.

3. Post-merge housekeeping

For PRs that merged since the previous pass (first pass: since session start — gh pr list --state merged --limit 10 --json number,mergedAt,files):

• Backend delta — if a merged PR touched functions/**, security/**, or firestore.indexes.json, run bash tool/pending_deploy.sh rihla-safar. If it reports pending, say so and point at the deploy-ceremony skill. NEVER deploy from here — the ceremony needs the user's Firebase auth and their eyes on the delta.
• Worktree GC — git worktree list. A non-main worktree is removable ONLY when ALL of:
  1. its branch's PR is merged: gh pr list --head <branch> --state merged --json number,headRefOid is non-empty;
  2. the worktree HEAD equals that PR's headRefOid (squash-merge means branch commits are never ancestors of main — comparing SHAs is the only safe test; a differing HEAD = commits made after the merge → surface, don't remove);
  3. git -C <worktree> status --porcelain is empty. Then git worktree remove <path> and delete the local branch. Anything dirty, unmerged, or ambiguous: leave it and report. Never --force.

4. Report the board

One line per PR: number, title, state, action taken this pass, what it's waiting on. Plus any pending-deploy reminder and worktrees GC'd/skipped.

/loop pacing

• Any tracked PR has CI running or was just updated → wake in ~270s (stay inside the prompt-cache window).
• Everything waiting on the human (P1s, conflicts, red CI) or nothing in flight → 1200s+.
• No open PRs, no pending deploy → end the loop and say the board is clear.

Non-negotiables

• Never gh pr merge without --auto. Only the automerge pipeline enables merging; this skill never bypasses it — not for "obviously safe" PRs either.
• Never override a P1 stop. A new push = a NEW /automerge round with fresh agents (never continue the old reviewer).
• Conflicts, red CI, and deploys belong to the human — surface, don't fix.
• Worktree removal requires merged PR + HEAD==merged SHA + clean tree. When in doubt, report instead of removing.