# NousResearch/hermes-agent · grep fallback extended regex alternation fix

## Open now

- Nothing open on GitHub.

These members address a bug where pipe-based alternation patterns silently return zero results in the grep fallback path. The fix involves enabling extended regex mode in grep to properly support alternation syntax.

## 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 #79782. Verify it addresses your case.
- **Recommended:** read PR #79782 (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-79782`. 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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

- #39294: search_files target='content' silently returns 0 results when pattern uses pipe (|) alternation on the grep fallback path

## Prior & competing PRs

- **#79782: fix(search): use extended regex in grep fallback for alternation support**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `tests/tools/test_file_operations_edge_cases.py`, `tests/tools/test_search_hidden_dirs.py`, `tools/file_operations.py`
- **#39298: fix(search): use extended regex in grep fallback for alternation support**. closed without merge
  - maintainer direction: category `superseded_by_pr`; implication `superseded`; refs `#79782`, `#39922`, `#39294`
- **#39922: fix(file): align grep fallback regex behavior**. closed without merge
  - maintainer direction: category `merged_via`; implication `superseded`; refs `#79782`, `#39298`

## Fix status

- Merged to main in PR #79782 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-08-06`.
- Subsystem: `agent`