The following errors were visible in a test_push log after a successful run. It appears there are at least 2 cleanup errors. Not sure how important.

[chromeos-autotest.hot.corp.google.com] run: find /usr/local/autotest//results/. | grep -v 'README' | xargs rm -rf
[chromeos-autotest.hot.corp.google.com] out: rm: cannot remove directory: ‘/usr/local/autotest//results/.’
[chromeos-autotest.hot.corp.google.com] out: 

Warning: run() received nonzero return code 123 while executing 'find /usr/local/autotest//results/. | grep -v 'README' | xargs rm -rf'!

2017-07-14 12:12:26,498 INFO| RunTestPushTask succeed.
2017-07-14 12:12:26,498 INFO| Printing out task report.

{
  "sub_reports": [],
  "exception": null,
  "is_successful": true,
  "description": "RunTestPushTask succeed.",
  "arguments_used": {},
  "task_name": "RunTestPushTask"
}
Exception in thread Thread-3 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
  File "/root/.cache/cros_venv/venv-2.7.6-0592ea92663037bb624f94a82dbb4eb5/local/lib/python2.7/site-packages/paramiko/transport.py", line 1794, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'