Traceback (most recent call last):
  File "/usr/local/autotest/site_utils/kill_slow_queries.py", line 167, in <module>
    sys.exit(main())
  File "/usr/local/autotest/site_utils/kill_slow_queries.py", line 162, in main
    ' backup server.\nTo avoid db crash, please check ASAP.') % e)
  File "/usr/local/autotest/site_utils/gmail_lib.py", line 177, in send_email
    backoff_factor=RETRY_BACKOFF_FACTOR)
  File "/usr/local/autotest/site-packages/chromite/lib/retry_util.py", line 243, in GenericRetry
    return _run()
  File "/usr/local/autotest/site-packages/chromite/lib/retry_util.py", line 176, in _Wrapper
    ret = func(*args, **kwargs)
  File "/usr/local/autotest/site-packages/chromite/lib/retry_util.py", line 242, in _run
    return functor(*args, **kwargs)
  File "/usr/local/autotest/site_utils/gmail_lib.py", line 155, in _run
    client.send_message(m, ignore_error=False)
  File "/usr/local/autotest/site_utils/gmail_lib.py", line 121, in send_message
    userId='me', body=message.get_payload()).execute()
  File "/usr/local/autotest/site-packages/chromite/third_party/oauth2client/util.py", line 140, in positional_wrapper
    return wrapped(*args, **kwargs)
  File "/usr/local/autotest/site-packages/chromite/third_party/googleapiclient/http.py", line 838, in execute
    raise HttpError(resp, content, uri=self.uri)
googleapiclient.errors.HttpError: <HttpError 400 when requesting https://www.googleapis.com/gmail/v1/users/me/messages/send?alt=json returned "Recipient address required">

kill_slow_queries should have a crash metric.