Successful Pipelines in a Merge Train are not merged or rescheduled when a preceding pipeline fails
Summary
User reporting the issue says that some pipelines in the Merge Train are successful but when a pipeline that ran before them fails those successful pipelines are not merged or rescheduled.
Steps to reproduce
Example A:
Pos 1.: MR 1 Pos 2.: MR 2 Pos 3.: MR 3 Pos N.: (All following got scheduled in the MTQueue.)
The First one failed in the Merge Train. The Second one successfully finished the pipeline but has dropped out of the MergeTrain, MergeRequest is still open. Expected behavior would be to see the successful pipeline rescheduled to the first position of the Merge Train. The Third pipeline was rescheduled to position one.
Example B:
Pos 1.: MR 1
The Merge Request pipeline is successfully completed but has dropped out of the Merge Train and the MergeRequest is still open. After manually re-trigger of the pipeline it merges successfully.
This behavior is intermittent (it does not happen consistently).
What is the current bug behavior?
Pipelines in the Merge Train are successful but when a pipeline that ran before them fails those successful pipelines are not merged or rescheduled.
What is the expected correct behavior?
Pipelines in the Merge Train that are successful should be merged or rescheduled when a pipeline that ran before them fails.
Relevant logs and/or screenshots
Workflow:
Results of GitLab environment info
GitLab 13.10.3