FYI, unless you strongly suspect a hardware/network issue, this should really go through the Trooper queue (label Infra-Troopers). Troopers can pass it off to Labs if it appears to be their issue (e.g. no email is going out anywhere, indicating the smtp gateway is down or something), which doesn't look like the case here.

The log is full of exceptions:

2016-08-23 13:46:07,782 - chromium - ERROR - Uncaught Exception in <chrome.bugdroid.poller_handlers.SentryPollerHandler object at 0x7f9738e1d610>
Traceback (most recent call last):
  File "/usr/local/google/home/chrome-cron/src/infra/infra_internal/py_issue_tracker/chrome/bugdroid/gitiles_poller.py", line 176, in _ProcessGitLogEntry
    handler.ProcessLogEntry(log_entry)
  File "/usr/local/google/home/chrome-cron/src/infra/infra_internal/py_issue_tracker/chrome/bugdroid/poller_handlers.py", line 134, in ProcessLogEntry
    default_to_project=True)
TypeError: get_issues() got an unexpected keyword argument 'project'

Oh, wait, #2 is a different problem (commitsentry). Yay for finding more bugs.

Restarting commitsentry fixed chromium-checkins.

Assigning to agable for the error in #2, which appears to be related to https://chrome-internal.googlesource.com/infra/infra_internal/+/a87fa0185df064862ad9e4448b80fe99bdd5dbff

https://chromereviews.googleplex.com/494997013

Not sure how these callsites were missed, nor how restarting it fixed anything??

Restarting didn't fix these broken calls, it just fixed sending the chromium-checkins emails, which is confusingly intertwined, yet somehow separate, from the sentry processing. These should probably be two completely separate tools, but "legacy", "technical debt", yada-yada.

The following revision refers to this bug:
  https://chrome-internal.googlesource.com/infra/infra_internal.git/+/0e9c125674510bef3e983cf681f962fa5f05664d

commit 0e9c125674510bef3e983cf681f962fa5f05664d
Author: agable <agable@google.com>
Date: Tue Aug 23 18:24:46 2016

CL has been deployed.