Pull request not merged

[rtc11]

How would you describe the issue?

Auto merge me from a workflow_run reports success with a generic error message.

How can we reproduce the issue? On a public repository, use this exact setup:

Follow this guide: https://stefanzweifel.io/posts/2021/04/28/auto-merge-dependabot-pull-requests

Comment the pull request with @dependabot rebase to trigger the workflow where github..actor = dependabot[bot]

What are the expected results? The pull request was merged

What are the actual results? The action reports success ✅ , the pull-request was not merged, but this message is logged to the action console:

An error occurred while merging the Pull Request. This is usually caused by the base branch being out of sync with the target branch. In this case, the base branch must be rebased. Some tools, such as Dependabot, do that automatically.

How much does it hurt? The action does not seem to work.