Spurious failures caused by GitLab's 50x responses
Runners sometimes get HTTP 502 or 504 responses from GitLab. So far, I've found 5 symptoms:
- When cloning the repo under test, which is unrecoverable.
- When cloning submodules, in which case git automatically retries and may succeed.
- When fetching perf notes, which is unrecoverable.
- When pushing perf notes, in which case ci/test-metrics.sh retries and may succeed.
- When uploading job archives, in which case gitlab-runner retries and may succeed.