Example build
https://uberchromegw.corp.google.com/i/chromeos_release/builders/arkham-release%20release-R59-9460.B/builds/6

@@@STEP_FAILURE@@@
00:25:08: ERROR: Traceback (most recent call last):
  File "/b/cbuild/repository/chromite/cbuildbot/stages/generic_stages.py", line 628, in Run
    self.PerformStage()
  File "/b/cbuild/repository/chromite/cbuildbot/stages/test_stages.py", line 416, in PerformStage
    ('Build', build_id, 'BuildStage', self._build_stage_id)})
  File "/b/cbuild/repository/chromite/lib/failures_lib.py", line 190, in wrapped_functor
    return functor(*args, **kwargs)
  File "/b/cbuild/repository/chromite/cbuildbot/commands.py", line 1019, in RunHWTestSuite
    _HWTestWait(cmd, job_id, **swarming_args)
  File "/b/cbuild/repository/chromite/cbuildbot/commands.py", line 1263, in _HWTestWait
    **kwargs)
  File "/b/cbuild/repository/chromite/cbuildbot/swarming_lib.py", line 153, in RunSwarmingCommandWithRetries
    return retry_util.RetryCommand(RunSwarmingCommand, max_retry, *args, **kwargs)
  File "/b/cbuild/repository/chromite/lib/retry_util.py", line 224, in RetryCommand
    return GenericRetry(ShouldRetry, max_retry, functor, *args, **kwargs)
  File "/b/cbuild/repository/chromite/lib/retry_util.py", line 122, in GenericRetry
    ret = functor(*args, **kwargs)
  File "/b/cbuild/repository/chromite/cbuildbot/swarming_lib.py", line 92, in RunSwarmingCommand
    result = cros_build_lib.RunCommand(swarming_cmd, *args, **kwargs)
  File "/b/cbuild/repository/chromite/lib/cros_build_lib.py", line 593, in RunCommand
    (cmd_result.output, cmd_result.error) = proc.communicate(input)
  File "/usr/lib/python2.7/subprocess.py", line 796, in communicate
    self.wait()
  File "/usr/lib/python2.7/subprocess.py", line 1376, in wait
    pid, sts = _eintr_retry_call(os.waitpid, self.pid, 0)
  File "/usr/lib/python2.7/subprocess.py", line 476, in _eintr_retry_call
    return func(*args)
  File "/b/cbuild/repository/chromite/lib/cros_build_lib.py", line 340, in _KillChildProcess
    if not signals.RelaySignal(original_handler, signum, frame):
  File "/b/cbuild/repository/chromite/lib/signals.py", line 26, in RelaySignal
    handler(signum, frame)
  File "/b/cbuild/repository/chromite/lib/commandline.py", line 733, in _DefaultHandler
    signum, 'Received signal %i; shutting down' % (signum,))
_ShutDownException: (15, 'Received signal 15; shutting down')

Link to logs:
https://uberchromegw.corp.google.com/i/chromeos_release/builders/arkham-release%20release-R59-9460.B/builds/6/steps/HWTest%20%5Bsanity%5D/logs/stdio