Gitlab Runner 500 during checking for jobs

Gitlab runner hitting the gitlab.com CI instance is getting 500s for some, but not all jobs.

Log entries when run with --debug:

WARNING: Checking for jobs... failed                runner=9e617c37 status=500 Internal Server Error 
Checking GitLab compatibility... OK                 runner=9e617c37 
Feeding runners to channel                          builds=0 
Checking for jobs... nothing                        runner=9e617c37