Sample failure,
02/02 14:17:47.572 WARNI|              test:0637| The test failed with the following exception
Traceback (most recent call last):
  File "/usr/local/autotest/client/common_lib/test.py", line 631, in _exec
    _call_test_function(self.execute, *p_args, **p_dargs)
  File "/usr/local/autotest/client/common_lib/test.py", line 831, in _call_test_function
    return func(*args, **dargs)
  File "/usr/local/autotest/client/common_lib/test.py", line 495, in execute
    dargs)
  File "/usr/local/autotest/client/common_lib/test.py", line 362, in _call_run_once_with_retry
    postprocess_profiled_run, args, dargs)
  File "/usr/local/autotest/client/common_lib/test.py", line 400, in _call_run_once
    self.run_once(*args, **dargs)
  File "/usr/local/autotest/server/site_tests/network_WiFi_IBSS/network_WiFi_IBSS.py", line 41, in run_once
    self.context.assert_connect_wifi(assoc_params)
  File "/usr/local/autotest/server/cros/network/wifi_test_context_manager.py", line 274, in assert_connect_wifi
    connect_name, assoc_result.failure_reason))
TestFail: Expected connection to IBSS_b_gqhrp_ch1 to succeed, but it failed with reason: FAIL(Association timed out).

https://stainless.corp.google.com/search?view=list&first_date=2018-01-01&last_date=2018-02-28&suite=wifi_matfunc&test=network_WiFi_IBSS.wifi_IBSS&board=bob&hostname=chromeos15-row1-rack3-host2&status=GOOD&status=FAIL&status=NOT_RUN&exclude_cts=true&exclude_not_run=false&exclude_non_release=true&exclude_au=true&exclude_acts=true&exclude_retried=true&exclude_non_production=true