Cairn

Windows MCP child process orphan leak fix

NousResearch/hermes-agent · cluster 61059 · apps/desktop

Data as of

Nothing open on GitHub. Fix merged in #101598. Check it covers your case.

The short answer

0open issues
0open PRs
5items grouped
Known?
Yes. 5 related items grouped here, 2 issues already closed.
Fix event
A fix was merged to main in PR #101598. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this partially resolved, deciding PR #123003. That is separate from the fix event.
Still open
Nothing open on GitHub.

On Windows, the parent-death watchdog that kills MCP stdio child processes was a POSIX-only no-op, causing orphaned node.exe processes to accumulate across session restarts. A fix extends the watchdog mechanism to cover Windows.

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.

  • #101598 perf(mcp): one parent-death supervisor per process instead of one per stdio server (salvage #93517)

    merged to main

    files: tests/tools/test_mcp_death_supervisor.py, tests/tools/test_mcp_stdio_watchdog.py, tools/browser_tool.py, tools/mcp_death_supervisor.py, tools/mcp_stdio_watchdog.py, tools/mcp_tool.py

  • #123003 fix(mcp): kill Windows stdio MCP orphan trees (Job Object + tree reaping)

    merged to main

    files: hermes_cli/process_identity.py, tests/tools/test_mcp_windows_orphan_fix.py, tools/mcp_tool_lifecycle.py, tools/mcp_tool_transport.py

1 PR closed without merging

From the close comments: superseded by another PR 1

  • #61089 fix(mcp): extend parent-death watchdog to Windows (Fixes #61059) · superseded by another PR → 95fa814, 0cd93f0, #101598, #61059
Closed issues · 2
  • Closed#61059Windows Desktop: MCP node.exe orphan accumulation across session restarts (40+ processes, 1.6GB, 228 event loop stalls)
  • Closed#63675Windows: MCP stdio children (gbrain serve) leak across sessions — watchdog is POSIX-only no-op
How this cluster was grouped
  • Link evidence (partly structural links): some members are connected by structural evidence (shared changed files, or a closing/superseded reference); the rest are joined by an automated relevance judgement over their text.
  • Members outside that structural core may belong to a different underlying problem.
  • Pairwise link density 0.34: 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.

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At a glance

Subsystem
apps/desktop
Merged PRs
#101598, #123003
Closed issues
2
Attempts
1 PR closed without merging
Fix link checked
27 Sep 2026

For your agent

The same facts, typed.

cluster/61059.json
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