# NousResearch/hermes-agent · MCP stdio command lookup mutates parent environment

## Open now

- Nothing open on GitHub.

These issues and PRs address a bug where MCP stdio command resolution incorrectly reads from or mutates the parent process's PATH and PATHEXT environment variables. Multiple fix attempts focus on isolating command lookup to the child environment only.

## 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 #117626. Verify it addresses your case.
- **Recommended:** read PR #117626 (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-117626`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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

- #117214: _which_with_config_pathext mutates the parent process's PATHEXT during MCP command lookup

## Prior & competing PRs

- **#117626: fix(mcp): stdio command lookup stops mutating PATHEXT and reading the parent PATH (#117214 #117213, salvage #117238)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `tests/tools/test_mcp_tool_issue_948.py`, `tools/mcp_tool_config.py`
- **#117219: fix(mcp): keep stdio command lookup inside the child env**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `9eca7f388f`, `#117626`
- **#117238: fix(mcp): resolve stdio commands without reading or mutating the parent env**. closed without merge
  - maintainer direction: category `merged_via`; implication `superseded`; refs `9eca7f388f`, `#117626`

## Fix status

- Merged to main in PR #117626 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-09-20`.