It seems that some updates made in the last two weeks to Jenkins plugins or GitHub api introduce a very strange behaviour on GitHub.

Now we can prevent a PR from being merged if a specific Jenkins branch-job is not green but somehow it seems impossible to check if current PR is green.

If we do not select any branch in github repository configuration Jenkins build will not happen and the user would be able to merge the change.

If we check one of them Jenkins will build it and as a surprise we can see the job name that is matching the PR name. Wonderful, but somehow it seems that the generic check named "Jenkins" is still waiting for another status check, one that will never happen, preventing us from merging.