Enforcing

By default LGTM reports and never blocks. Turning that around takes two things, and both must be true:

1. enforce: true in .github/lgtm.yml.
2. LGTM — review confirmed marked as a required status check in the repository's branch protection rule or ruleset.

LGTM does not request the permissions that would let it do step 2 for you. A tool that can grant itself the power to block merges is a different and worse thing.

With both on, an unanswered quiz leaves the check incomplete, which holds the merge until someone answers it.

Releasing a merge without answering

Comment /lgtm waive on the pull request. Anyone who could already merge it can waive it, meaning OWNER, MEMBER or COLLABORATOR, and the waiver is recorded in the thread rather than applied quietly.

The waiver exists because the alternative is worse. A reviewer who cannot answer a question at 6pm on a Friday will find a way around the tool, and a recorded waiver is a better outcome than a disabled check.

What can never block

A check LGTM concluded neutral never holds a merge, and every LGTM-side problem lands there:

• the model failed or the vendor is down
• no API key is configured
• the diff produced no question that survived verification
• the pull request is too large to quiz
• the configuration file could not be read

So LGTM being broken cannot freeze a repository. That is the property the neutral conclusion exists to protect.

A failure conclusion is never used at all. It is the only conclusion that would put a red X on a pull request, and this tool has no business doing that to someone who read the diff and answered honestly.