Sometimes, for different reasons, you need to run a job that has been triggered again.
It could be because of a communication error with the git repo or the connection to Gerrit went down when the approve command was supposed to be sent.
Instead of creating a new patch and upload it to Gerrit it should be possible to click a button that runs the job again and reports the result back to Gerrit.
Retrigger one job: Rebuild just one job, if multiple jobs where triggered before the build results from the old jobs should count in the final approve report.
Retrigger all jobs: Rebuild all jobs that was triggered before on the patchset event.