Example build:
https://luci-milo.appspot.com/buildbot/chromeos/cave-paladin/2809

Error log:
https://logs.chromium.org/v/?s=chromeos%2Fbb%2Fchromeos%2Fcave-paladin%2F2809%2F%2B%2Frecipes%2Fsteps%2FHWTest__bvt-inline_%2F0%2Fstdout

Error:
IndexError: list index out of range
11:10:04: ERROR: Failed to parse HWTest JSON dump string, subsystem based partial submission will be skipped:  Invalid swarming output: Traceback (most recent call last):
  File "/usr/local/autotest/site_utils/run_suite.py", line 2110, in <module>
    sys.exit(main())
  File "/usr/local/autotest/site_utils/run_suite.py", line 2093, in main
    result = _run_task(options)
  File "/usr/local/autotest/site_utils/run_suite.py", line 2030, in _run_task
    return _run_suite(options)
  File "/usr/local/autotest/site_utils/run_suite.py", line 1802, in _run_suite
    return _handle_job_wait(afe, job_id, options, job_timer, is_real_time)
  File "/usr/local/autotest/site_utils/run_suite.py", line 1904, in _handle_job_wait
    collector.run()
  File "/usr/local/autotest/site_utils/run_suite.py", line 1608, in run
    self._generate_web_and_buildbot_links()
  File "/usr/local/autotest/site_utils/run_suite.py", line 1442, in _generate_web_and_buildbot_links
    suite_job_keyvals = self._suite_views[0]['job_keyvals']
IndexError: list index out of range