A pull request is pending when it has been marked as ready-to-merge but is not yet ready to enter the queue for some reason.
MergeQueue will validate all the necessary pre-conditions (such as passing all required checks, having no merge conflicts, and having sufficient approvals) before the pull request enters the queue.
Generally, a pull request is pending if it will enter the queue without any action from the pull request author (for example, the pull request is still running some required tests when the check_mergeability_to_queue setting is enabled).
When a pull request is pending, Aviator will report the reason why it has not yet entered the queue on the pull request sticky comment.
A pull request is queued when it has been marked as ready-to-merge and has passed all the necessary queue pre-conditions.
Once queued, MergeQueue will validate the changes in the pull request against the latest changes in the target branch (depending on the repository's queue mode) and merge the pull request if it passes all the required checks.
A pull request is blocked if it cannot not be merged and requires action from the pull request author (such as resolving merge conflicts or fixing broken tests).
Possible reasons for a pull request to be blocked include:
There was a merge conflict with the target branch or another pull request in the queue.
One or more of the required checks failed.
Approvals were removed from the pull request after it entered the queue.
The HEAD commit of the pull request was modified after it was marked as ready-to-merge.