I restarted Zuul and Jenkins a few minutes before that bug got filled. Investigating.

What happened is that I shutdown Jenkins and Zuul. Restarted Zuul which came up with non jobs registered at all (since Jenkins was down, it obviously could not register any job).

Some changes have been sent and interpreted by Zuul which reported the jobs do not exist (NOT_REGISTERED).

Whenever Jenkins came back, it registered the job again which make them available to Zuul.

I used 'recheck' on the above change and the jobs are running properly.

Not sure of a good way to prevent that. Maybe Zuul should not be restarted until Jenkins is ready, but then we will just drop Gerrit events.