babysit-stale-watchdog

name	babysit-stale-watchdog
description	Detect enabled babysit crons whose referenced PR is MERGED or CLOSED and disable them. Companion to the in-script `is_pr_terminal()` check in babysit.py. Without this watchdog, babysit crons can run hundreds of polls for weeks after the PR they were guarding has merged or closed.
trigger	Run every 30 min via launchd. Also manually via `python3 ~/.hermes/scripts/babysit_stale_watchdog.py`.

🚨 IF YOU ARE READING THIS BECAUSE THE USER ASKED WHY A THREAD IS FULL OF CRON SPAM, JUMP TO references/echo-loop-stale-babysit-recovery.md FIRST 🚨

The recovery recipe there is the single-call cleanup. Do not read the rest of this SKILL.md until the babysit is cancelled and the thread is quiet. Companion skill for the loop half: gateway-loop-standdown (read its top-of-file warning before posting any reply in that noisy thread).

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babysit-stale-watchdog

Why

Bug-ref: 2026-07-03 — babysit-wa-2403-PR7711 fired 251 polls over 11 days after PR #7711 merged. The original babysit.py only recognized "PR created" (a worker output event) as terminal, not "PR MERGED on GitHub" (an external event). The cron kept spamming Slack with "TERMINAL: merged" pings until Jeffrey noticed.

What

Two-layer fix:

1. In-script (babysit.py is_pr_terminal()): poll() now extracts any PR ref from the task_summary, calls gh pr view --json state, and if the PR is MERGED or CLOSED, posts one terminal message and exits the babysit loop. 19/19 tests pass.

2. Watchdog (babysit_stale_watchdog.py): belt-and-suspenders. Runs every 30 min via launchd. Even if babysit.py is broken or running against an old prompt, the watchdog catches the stale job and disables it within 30 min. 9/9 tests pass.

Install

# 1. Copy template to deployed plist (substitute @HOME@)
cp ~/.hermes/launchd/ai.hermes.schedule.babysit-stale-watchdog.plist.template \
   ~/Library/LaunchAgents/ai.hermes.schedule.babysit-stale-watchdog.plist

# 2. Verify syntax
plutil -lint ~/Library/LaunchAgents/ai.hermes.schedule.babysit-stale-watchdog.plist

# 3. Load + start
launchctl load -w ~/Library/LaunchAgents/ai.hermes.schedule.babysit-stale-watchdog.plist
launchctl kickstart -k gui/$(id -u)/ai.hermes.schedule.babysit-stale-watchdog

# 4. Verify it's running
launchctl list | grep babysit-stale-watchdog
tail -5 ~/.hermes/cron/output/babysit-stale-watchdog.log

Verify

# Run once manually
python3 ~/.hermes/scripts/babysit_stale_watchdog.py

# Run unit + e2e tests
python3 ~/.hermes/scripts/tests/test_babysit_stale_watchdog.py    # 9 tests
python3 ~/.hermes/skills/ao-babysit/scripts/test_babysit_pr_exit.py  # 19 tests

Files

• ~/.hermes/scripts/babysit_stale_watchdog.py — the watchdog
• ~/.hermes/scripts/tests/test_babysit_stale_watchdog.py — 9 tests
• ~/.hermes/skills/ao-babysit/scripts/babysit.py — restored + patched with is_pr_terminal()
• ~/.hermes/skills/ao-babysit/scripts/test_babysit_pr_exit.py — 19 tests
• ~/.hermes/launchd/ai.hermes.schedule.babysit-stale-watchdog.plist.template — committed plist template

Pitfalls

• babysit.py was deleted in commit 4a7befcfa4 (squash-merge of feat/hermes-agent-default into main) — only the .pyc survived. Every cron prompt that referenced python3 ~/.hermes/skills/ao-babysit/scripts/babysit.py poll ... was failing silently. Restored from git show 4a7befcfa4^:skills/ao-babysit/scripts/babysit.py plus the new merged-PR check.

• Default repo for bare PR #NNNN refs: defaults to $GITHUB_REPOSITORY since that's the most common babysit target (5 of 5 in the 2026-07-03 sweep). If babysits for other repos get created, the URL form https://github.com/o/r/pull/N is exact — prefer that.

• Parked-handoff end-state (worker never spawned) — see references/worker-not-spawned-parked-handoff.md for the three-way check (session + PR + operator reply) and the verbatim cancel recipe. Verified 2026-07-22 on cron 5a771c731157 (thread C0AH3RY3DK6/p1784721612.183329); this is the third end-state the watchdog catches, alongside PR-MERGED and PR-CLOSED.

• gh failures fall through to "not terminal" — if gh is down or rate-limited, the watchdog leaves the job enabled rather than disabling it. The in-script is_pr_terminal() has the same fallback.

• cronjob CLI may not exist on PATH (verified 2026-07-31, thread C09GRLXF9GR/p1784235989.925899): the recovery recipe in references/echo-loop-stale-babysit-recovery.md assumes cronjob action=remove job_id=<id> works, but cronjob returned command not found from the gateway session. ~/.hermes/scripts/cronjob* files absent, hermes_tools Python module not importable. When the recovery recipe's cronjob invocation fails, fall back in this order: (a) launchctl bootout gui/$(id -u)/ai.hermes.schedule.cronjob-<name> if the babysit runs under a named launchd plist; (b) look for a cronjob dispatcher under ~/.local/bin/, ~/.hermes/bin/, or ~/bin/ — many Hermes installs put it there rather than on PATH; (c) ask the user to type stop reminder <babysit-name> in-thread (the babysit prints this hint itself); (d) treat the babysit as an external system you cannot cancel and focus on the closeout post instead. Do NOT loop on "tool not found" — pick one fallback, post the closeout, and stop.

Companion pattern — no-agent hermes cron PR watchdog

For PRs that don't need an AO worker babysit, use hermes cron create --no-agent --script <watch-script>.sh to run a bash polling script on a fixed cadence. The script exits silently except on state transitions (OPEN with failures / OPEN with all-green / MERGED / CLOSED). Zero LLM tokens burned, instant state-transition pings to a Slack thread. See references/no-agent-hermes-cron-pr-watchdog.md for the full recipe plus the verified worked example (PR 8466 cron 124ad03896f5, 2026-07-20).

The script writes MERGED/CLOSED to its state file and exits 0; the launchd babysit-stale-watchdog cron disables the stale cron within 30 min via this skill.

First-time investigation recipe (when you arrive at a thread that's already full of babysit noise)

If a user surfaces a thread where a babysit cron has been spamming rate-limit errors for days/weeks (the cron is stale, the PR is already MERGED/CLOSED, but nobody canceled the cron), use references/stale-babysit-investigation-recipe.md for the 5-step investigate → cancel → verify recipe. Verified 2026-07-31 (cron 124ad03896f5, ~40 noise posts/day for 7 days).