https://screenshot.googleplex.com/VA39Zv9L61F.png

9184863483233739920 (FAILED):
[01:16:58.639] Failed to add buildbucket build - googleapi: Error 503: , backendError
[01:16:58.639] Invocation finished in 85.324623ms with status FAILED
[01:16:58.639] It will probably be retried

next one (OVERRUN):
[01:20:01.145] New invocation should be starting now, but previous one is still running: 9184863483233739920
[01:20:01.145] Total overruns thus far: 1

next one (stuck in RUNNING):
buildbucket ID: 9019432992606216256
swarming task ID: https://chromium-swarm-dev.appspot.com/user/task/2d4897b0dbff1f10

Swarming thinks it is complete, bb also thinks it is complete.

Swarming notified bb:
"""
Sending PubSub notify to "projects/cr-buildbucket-dev/topics/swarming" (with userdata "{"created_ts": 1456795428692840, "swarming_hostname": "chromium-swarm-dev.appspot.com"}") about completion of "2d4897b0dbff1f10"
"""

bb received the notification:
"""
17:28:07.555 Task id: 2d4897b0dbff1f10
17:28:07.656 Build id: 9019432992606216256
"""

Can't find where it sends notification to luci-cron...