hermes-agent/cron
entropy-0x abc349bd79 fix(cron): isolate per-job TERMINAL_CWD from concurrent cron jobs
A cron job with a per-job `workdir` overrides the process-global
`os.environ["TERMINAL_CWD"]` for the entire duration of its agent run and
restores it afterwards. The scheduler dispatches workdir jobs on a
single-thread sequential pool and workdir-less jobs on a separate parallel
pool, and the in-code comments claimed this made the override safe.

That only prevents two workdir jobs from overlapping each other. The two
pools run concurrently in the same process and share `os.environ`, so while
a workdir job has `TERMINAL_CWD` pointed at its project directory, any
workdir-less job firing in the same window reads that same global through the
terminal, file, and code-exec tools and runs its commands in the wrong
directory. The corruption window spans the whole workdir-job run, and a file
write or delete can land in another job's tree.

This serializes the override with a writer-preferring readers-writer lock.
Workdir jobs acquire it as writers (exclusive for their whole run); workdir-
less jobs acquire it as readers, so they still run in parallel with each
other but never alongside a workdir job's override. The guarantee is based on
run overlap rather than tick boundaries, so it also holds when a workdir job
spans ticks.

## What does this PR do?

Fixes a directory-isolation bug in the cron scheduler: a workdir cron job's
process-global `TERMINAL_CWD` override could be observed by a concurrently
running workdir-less cron job, causing that job's shell/file/code-exec
commands to execute in the wrong directory.

## Related Issue

N/A

## Type of Change

- [x] 🐛 Bug fix (non-breaking change that fixes an issue)
- [ ]  New feature (non-breaking change that adds functionality)
- [ ] 🔒 Security fix
- [ ] 📝 Documentation update
- [ ]  Tests (adding or improving test coverage)
- [ ] ♻️ Refactor (no behavior change)
- [ ] 🎯 New skill (bundled or hub)

## Changes Made

- `cron/scheduler.py`: add `_ReadWriteLock` (writer-preferring) and the
  module-global `_terminal_cwd_lock`.
- `cron/scheduler.py`: in `run_job`, acquire the lock as a writer for workdir
  jobs and as a reader for workdir-less jobs, spanning the `TERMINAL_CWD`
  override and its restore in the `finally` block.
- `cron/scheduler.py`: correct the stale comments in `run_job` and `tick` that
  claimed the sequential pool alone made the override safe.
- `tests/cron/test_terminal_cwd_lock.py`: new tests for reader concurrency,
  writer exclusion, and the no-cross-observation regression.

## How to Test

1. `python -m pytest tests/cron/test_terminal_cwd_lock.py -q` — the regression
   test `test_reader_never_observes_writer_override` fails without the lock and
   passes with it.
2. `python -m pytest tests/cron/test_cron_workdir.py tests/cron/test_parallel_pool.py -q`
   — confirms the existing `TERMINAL_CWD` set/restore and pool behaviour are
   unchanged.

## Checklist

### Code

- [x] I've read the Contributing Guide
- [x] My commit messages follow Conventional Commits (`fix(scope):`, etc.)
- [x] I searched for existing PRs to make sure this isn't a duplicate
- [x] My PR contains only changes related to this fix
- [x] I've run the affected `tests/cron/` suites and all tests pass
- [x] I've added tests for my changes (required for bug fixes)
- [x] I've tested on my platform: macOS 15 (Darwin 25.5)

### Documentation & Housekeeping

- [x] I've updated relevant documentation (docstrings/comments) — or N/A
- [x] I've updated `cli-config.yaml.example` if I added/changed config keys — N/A
- [x] I've updated `CONTRIBUTING.md` or `AGENTS.md` if I changed architecture — N/A
- [x] I've considered cross-platform impact (Windows, macOS) — uses stdlib `threading` only
- [x] I've updated tool descriptions/schemas if I changed tool behavior — N/A
2026-07-01 15:39:48 +05:30
..
scripts fix(cron-recipes): pre-release hardening — honest cadences, strict slot names, surface-aware UX 2026-06-11 10:49:47 -07:00
__init__.py docs: clarify gateway service scopes (#1378) 2026-03-14 21:17:41 -07:00
blueprint_catalog.py docs: finish Automation Blueprints terminology rebrand (#44470) 2026-06-11 17:22:22 -04:00
jobs.py fix(gateway,cron): guard cron model-tool path + add auto-resume loop breaker (#30719) 2026-07-01 02:48:36 -07:00
lifecycle_guard.py fix(gateway,cron): guard cron model-tool path + add auto-resume loop breaker (#30719) 2026-07-01 02:48:36 -07:00
scheduler.py fix(cron): isolate per-job TERMINAL_CWD from concurrent cron jobs 2026-07-01 15:39:48 +05:30
scheduler_provider.py fix(cron): avoid provider package shadowing core cron 2026-06-23 23:39:22 -07:00
suggestion_catalog.py fix(cron-recipes): pre-release hardening — honest cadences, strict slot names, surface-aware UX 2026-06-11 10:49:47 -07:00
suggestions.py fix(cron): make per-profile cron isolation intentional and tested (#4707) (#53570) 2026-06-27 03:55:01 -07:00