Cairn
NousResearch/hermes-agent

MCP stdio watcher coroutine leak fixes

Cluster 95938. Data as of

Nothing open on GitHub. Fix merged in #100920 on 2 Sep 2026. Check it covers your case.

The short answer

0open issues
0open PRs
5items grouped
Known?
Yes. 5 related items grouped here, 1 issue already closed.
Fix event
A fix was merged to main in PR #100920. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #100920. That is separate from the fix event.
Still open
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.

Open issues0

No open issues.

Open PRs0

No open pull requests.

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

  • #100920 fix(mcp): stdio tool calls no longer leak an un-awaited watcher coroutine per call (#95938, salvage #96251)

    merged to main

    files: tests/tools/test_mcp_stdio_children_dead.py, tools/mcp_tool.py

3 PRs closed without merging

From the close comments: done elsewhere 1 · duplicate 1 · other 1

  • #95939 fix(mcp): stop leaking the _watch_stdio_children coroutine on raced calls · other → #95938, #96044, #96251, #96030
  • #96251 fix(mcp): stop leaking an unawaited watcher coroutine per stdio tool call (salvage #96044) · done elsewhere → fe3e5dc, #100920
  • #100110 fix(mcp): don't instantiate _watch_stdio_children just to probe awaitability · duplicate → #96251
Closed issues · 1
  • Closed#95938MCP tool calls leak _watch_stdio_children coroutine during awaitability check
How this cluster was grouped
  • Link evidence (structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
  • Pairwise link density 0.40: the share of item 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.

Pick up a Lab task

Check whether a fix covers the open issues here, with your own agent. Bring back evidence for maintainers.

Open the Lab

At a glance

Merged PRs
#100920
Closed issues
1
Attempts
3 PRs closed without merging
Fix link checked
2 Sep 2026

For your agent

The same facts, typed.

cluster/95938.json
cluster/95938.md