# NousResearch/hermes-agent · MCP stdio watcher coroutine leak fixes

## Open now

- Nothing open on GitHub.

Multiple fixes and a related bug report addressing unawaited \`_watch_stdio_children\` coroutine leaks occurring during MCP stdio tool calls, including an awaitability probe and race condition scenario.

## TL;DR

- 5 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 3 PR(s) closed without merging.
- A fix was merged to main in PR #100920. Verify it addresses your case.
- **Recommended:** read PR #100920 (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-100920`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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 `0.40`: 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

- #95938: MCP tool calls leak _watch_stdio_children coroutine during awaitability check

## Prior & competing PRs

- **#100920: fix(mcp): stdio tool calls no longer leak an un-awaited watcher coroutine per call (#95938, salvage #96251)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `tests/tools/test_mcp_stdio_children_dead.py`, `tools/mcp_tool.py`
- **#95939: fix(mcp): stop leaking the _watch_stdio_children coroutine on raced calls**. closed without merge
  - maintainer direction: category `uncategorized`; implication `needs_llm`; refs `#95938`, `#96044`, `#96251`, `#96030`
- **#96251: fix(mcp): stop leaking an unawaited watcher coroutine per stdio tool call (salvage #96044)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `fe3e5dcb9ef`, `#100920`
- **#100110: fix(mcp): don't instantiate _watch_stdio_children just to probe awaitability**. closed without merge
  - maintainer direction: category `duplicate_of`; implication `duplicate`; refs `#96251`

## Fix status

- Merged to main in PR #100920 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-09-02`.