Merge request pipeline troubleshooting

When working with merge request pipelines, you might encounter the following issues.

Two pipelines when pushing to a branch

If you get duplicate pipelines in merge requests, your pipeline might be configured to run for both branches and merge requests at the same time. Adjust your pipeline configuration to avoid duplicate pipelines.

In GitLab 13.7 and later, you can add workflow:rules to switch from branch pipelines to merge request pipelines. After a merge request is open on the branch, the pipeline switches to a merge request pipeline.

Two pipelines when pushing an invalid CI/CD configuration file

If you push an invalid CI/CD configuration to a merge request's branch, two failed pipelines appear in the pipelines tab. One pipeline is a failed branch pipeline, the other is a failed merge request pipeline.

When the configuration syntax is fixed, no further failed pipelines should appear. To find and fix the configuration problem, you can use:

• The pipeline editor.
• The CI lint tool.

The merge request's pipeline is marked as failed but the latest pipeline succeeded

It's possible to have both branch pipelines and merge request pipelines in the Pipelines tab of a single merge request. This might be by configuration, or by accident.

When the project has Pipelines must succeed enabled and both pipelines types are present, the merge request pipelines are checked, not the branch pipelines.

Therefore, the MR pipeline result is marked as unsuccessful if the merge request pipeline fails, independently of the branch pipeline result.

However:

• These conditions are not enforced.
• A race condition determines which pipeline's result is used to either block or pass merge requests.

This bug is tracked on issue 384927.

An error occurred while trying to run a new pipeline for this merge request.

This error can happen when you select Run pipeline in a merge request, but the project does not have merge request pipelines enabled anymore.

Some possible reasons for this error message:

• The project does not have merge request pipelines enabled, has no pipelines listed in the Pipelines tab, and you select Run pipelines.

• The project used to have merge request pipelines enabled, but the configuration was removed. For example:

  1. The project has merge request pipelines enabled in the .gitlab-ci.yml configuration file when the merge request is created.
  2. The Run pipeline options is available in the merge request's Pipelines tab, and selecting Run pipeline at this point likely does not cause any errors.
  3. The project's .gitlab-ci.yml file is changed to remove the merge request pipelines configuration.
  4. The branch is rebased to bring the updated configuration into the merge request.
  5. Now the pipeline configuration no longer supports merge request pipelines, but you select Run pipeline to run a merge request pipeline.

If Run pipeline is available, but the project does not have merge request pipelines enabled, do not use this option. You can push a commit or rebase the branch to trigger new branch pipelines.

Merge blocked: pipeline must succeed. Push a new commit that fixes the failure message

This message is shown if the merge request pipeline, merged results pipeline, or merge train pipeline has failed or been canceled. This does not happen when a branch pipeline fails.

If a merge request pipeline or merged result pipeline was canceled or failed, you can:

• Re-run the entire pipeline by selecting Run pipeline in the pipeline tab in the merge request.
• Retry only the jobs that failed. If you re-run the entire pipeline, this is not necessary.
• Push a new commit to fix the failure.

If the merge train pipeline has failed, you can:

• Check the failure and determine if you can use the /merge quick action to immediately add the merge request to the train again.
• Re-run the entire pipeline by selecting Run pipeline in the pipeline tab in the merge request, then add the merge request to the train again.
• Push a commit to fix the failure, then add the merge request to the train again.

If the merge train pipeline was canceled before the merge request was merged, without a failure, you can:

• Add it to the train again.