I've configured Jenkins git pull request plugin according to docs: https://wiki.jenkins-ci.org/display/JENKINS/GitHub+pull+request+builder+plugin but build returns to me
ERROR: Couldn't find any revision to build. Verify the repository and branch configuration for this job.
If I leave "Branch Specifier" empty, Jenkinks goes through every PR (even closed) in my repo. How to force it to build only open PR?