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[Bug] prepare-commit-msg hook blocks every commit on LLM latency with no overall timeout #271
Description
Summary
The prepare-commit-msg hook runs buildProfile() + generateSuggestions() synchronously inside the git commit path. The hook has no overall deadline of its own — a slow or stalled provider delays every commit for up to the per-request timeout (30s, src/providers/request.ts:1), and a provider outage adds seconds of latency to each commit before degrading to a warning. To an end user, git commit appears to hang.
Location
src/git/hook.ts:196-208—runPrepareCommitMsgHook: LLM calls block commitsrc/providers/request.ts:1—DEFAULT_PROVIDER_REQUEST_TIMEOUT_MS = 30_000
Code snippet
// src/git/hook.ts (inside prepare-commit-msg, blocks `git commit`)
const profile = await deps.buildProfile(config.historySize);
const { suggestions } = await deps.generateSuggestions(config, diffResult.diff, profile);
const selected = suggestions[0];
...
await deps.writeMessageFile(args.messageFile, nextContent);Suggested fix
Give the hook a tight overall deadline (e.g. abort suggestion generation after a few seconds and leave the commit message unchanged), so provider slowness can never block a commit for the full 30s. Consider also skipping the LLM call entirely when the provider appears unreachable (fast health check) or when --no-verify semantics apply.
Impact
- Every commit's latency is coupled to LLM provider health; a hung provider stalls all commits for up to 30s each.
- Users who install the hook and later hit a provider outage perceive git itself as broken.
Activity
404-Page-Found commentedon Sep 22, 2026
Triage update:
Confirmed on current
main:runPrepareCommitMsgHook()awaitsbuildProfile()andgenerateSuggestions()directly on thegit commitpath.DEFAULT_PROVIDER_REQUEST_TIMEOUT_MS, so a slow/unreachable provider can makegit commitappear hung.fetchWithTimeout()clears its timer once response headers arrive, while non-streaming providers then awaitresponse.json(). A stalled response body can therefore exceed the nominal 30s timeout.Recommended fix:
A simple
Promise.race()timeout without cancellation is not sufficient because the underlying provider request could continue after the hook returns.404-Page-Found commentedon Sep 22, 2026
Implemented the fix in PR #322: #322. The prepare-commit-msg path now has a 5s overall deadline with abort propagation, keeps provider timeouts active through non-streaming response-body reads, and leaves the commit message unchanged on timeout. Regression coverage was added for both a stalled hook request and a stalled response body.
fix: bound prepare-commit-msg hook latency (#271) (#322)