# NousResearch/hermes-agent · MCP orphan reaper PGID recycling safety fixes

## Open now

- Nothing open on GitHub.

These issues and PRs address a bug where the orphan MCP process reaper could send SIGTERM to unrelated processes if a process group ID (PGID) was recycled by the OS. The work involves adding per-process PID isolation, PGID ownership re-validation, and guards against this unsafe kill behavior.

## TL;DR

- 4 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 2 PR(s) closed without merging.
- A fix was merged to main in PR #131910. Verify it addresses your case.
- **Recommended:** read PR #131910 (and any competing PRs below) before filing. Confirm the merged change covers your symptom.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `resolved` · deciding PR(s): `pr-131910`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.50`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #43044: Gateway orphan-MCP reaper can SIGTERM an unrelated process via a recycled PGID

## Prior & competing PRs

- **#131910: fix(mcp): re-validate PGID ownership before killing orphaned process groups \[risk 0.20\]**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `tests/tools/test_mcp_stability.py`, `tools/environments/local.py`, `tools/mcp_tool_lifecycle.py`, `tools/mcp_tool_transport.py`
- **#43046: fix(mcp): re-validate PGID ownership before killing orphaned process groups**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `#131910`
- **#43135: fix(mcp): guard orphan reaper against recycled PGID killing unrelated processes**. closed without merge
  - maintainer direction: category `uncategorized`; implication `needs_llm`

## Fix status

- Merged to main in PR #131910 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-10-03`.
- Subsystem: `gateway`