## Summary `Gitlab::Git::KeepAround#execute` rescues `Gitlab::Git::CommandError` and only tracks the exception via `Gitlab::ErrorTracking.track_exception`. This means when a Gitaly call fails (e.g. timeout), the keep-around ref is **not created** and **no error is surfaced** to the caller. The MR diff or merge request is created successfully, but the commit SHAs are left unprotected from garbage collection. https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/git/keep_around.rb#L48-L49 ```ruby rescue Gitlab::Git::CommandError => ex Gitlab::ErrorTracking.track_exception(ex, object_id: sha) ``` ## Problem 1. `CommandError` (e.g. Gitaly timeout) is silently rescued — the caller has no idea the keep-around ref was not written 2. If Git GC runs after this silent failure, the commit objects may be pruned 3. This can lead to **silent data loss** — merge request diffs referencing commits that no longer exist 4. The failure is only visible in error tracking (Sentry), not in application logs or user-facing errors 5. As noted in the [MR discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/223665#note_3088100699), `CommandError` is only one of many Gitaly errors (see [`wraps_gitaly_errors.rb`](https://gitlab.com/gitlab-org/gitlab/-/blob/master/lib/gitlab/git/wraps_gitaly_errors.rb)), but it is the one most likely to occur (e.g. timeouts) and the one being silently swallowed ## Expected behavior When `keep_around_commits` fails, the failure should either: - Fail loudly so the problem can be detected and addressed, or - Be logged with sufficient severity to trigger alerts ## Proposal Determine the appropriate error handling strategy for this code path. Options discussed in the related MR: 1. **Remove the rescue** and let the error propagate — ensures failures are visible but may impact MR diff creation 2. **Add structured logging / alerting** — keep the rescue but ensure failures are surfaced more visibly ## Related - Discussion: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/223665#note_3088100699 - Related issue: https://gitlab.com/gitlab-org/gitlab/-/issues/589480