tricky-tot-chrome-pfq-informational

https://cros-goldeneye.corp.google.com/chromeos/healthmonitoring/buildDetails?buildbucketId=8945057005004984816

05/30 19:32:44.505 DEBUG|   user_crash_test:0296| Crasher process result: {'crashed': True, 'returncode': 139, 'output': 'pid=18512\nCrashing as requested.\n', 'crash_reporter_caught': True}
05/30 19:32:44.507 DEBUG|   user_crash_test:0402| Contents in /home/chronos/crash: ['crasher_nobreakpad.20180530.193244.18512.dmp', 'crasher_nobreakpad.20180530.193244.18512.meta']
05/30 19:32:44.507 DEBUG|             utils:0215| Running 'ls -tr1 /var/log/messages.*'
05/30 19:32:44.519 DEBUG|             utils:0215| Running '/usr/bin/minidump_stackwalk /home/chronos/crash/crasher_nobreakpad.20180530.193244.18512.dmp /usr/local/autotest/tests/logging_UserCrash/src/crasher/symbols'
05/30 19:32:44.546 DEBUG|   user_crash_test:0142| minidump_stackwalk output:
Operating system: Linux
                  0.0.0 Linux 3.8.11 #1 SMP Wed May 30 09:56:07 PDT 2018 x86_64
CPU: amd64
     family 6 model 69 stepping 1
     1 CPU

GPU: UNKNOWN

Crash reason:  SIGSEGV /0x00000000
Crash address: 0x0
Process uptime: not available

Thread 0 (crashed)
 0  crasher_nobreakpad!recbomb(int) [bomb.cc : 9 + 0x0]
    rax = 0x1b14cedf494b3400   rdx = 0x0000000000000017
    rcx = 0x00007fcb5347c8e0   rbx = 0x0000000000000000
    rsi = 0x00007fcb5347c8e0   rdi = 0x0000000000000001
    rbp = 0x00007ffca5c15460   rsp = 0x00007ffca5c15448
     r8 = 0x00007fcb53885700    r9 = 0x0000000000000017
    r10 = 0x00007fcb53885700   r11 = 0x0000000000000246
    r12 = 0x00007fcb539aef40   r13 = 0x00007ffca5c15730
    r14 = 0x0000000000000000   r15 = 0x0000000000000000
    rip = 0x00007fcb539aef05
    Found by: given as instruction pointer in context
 1  crasher_nobreakpad!recbomb(int) [bomb.cc : 12 + 0x5]
    rbx = 0x0000000000000000   rbp = 0x00007ffca5c15460
    rsp = 0x00007ffca5c15450   r12 = 0x00007fcb539aef40
    r13 = 0x00007ffca5c15730   r14 = 0x0000000000000000
    r15 = 0x0000000000000000   rip = 0x00007fcb539aef20
    Found by: call frame info
...
05/30 19:32:44.565 WARNI|              test:0637| The test failed with the following exception
Traceback (most recent call last):
  File "/usr/local/autotest/common_lib/test.py", line 631, in _exec
    _call_test_function(self.execute, *p_args, **p_dargs)
  File "/usr/local/autotest/common_lib/test.py", line 831, in _call_test_function
    return func(*args, **dargs)
  File "/usr/local/autotest/common_lib/test.py", line 495, in execute
    dargs)
  File "/usr/local/autotest/common_lib/test.py", line 362, in _call_run_once_with_retry
    postprocess_profiled_run, args, dargs)
  File "/usr/local/autotest/common_lib/test.py", line 400, in _call_run_once
    self.run_once(*args, **dargs)
  File "/usr/local/autotest/tests/logging_UserCrash/logging_UserCrash.py", line 322, in run_once
    initialize_crash_reporter=True)
  File "/usr/local/autotest/cros/crash/crash_test.py", line 711, in run_crash_tests
    getattr(self, '_test_' + test_name)()
  File "/usr/local/autotest/tests/logging_UserCrash/logging_UserCrash.py", line 64, in _test_chronos_crasher
    self._check_crashing_process('chronos')
  File "/usr/local/autotest/cros/crash/user_crash_test.py", line 482, in _check_crashing_process
    from_crash_reporter=True)
  File "/usr/local/autotest/cros/crash/user_crash_test.py", line 329, in _check_minidump_stackwalk
    self._verify_stack(stack, basename, from_crash_reporter)
  File "/usr/local/autotest/cros/crash/user_crash_test.py", line 152, in _verify_stack
    raise error.TestFail('Did not identify SIGSEGV cause')
TestFail: Did not identify SIGSEGV cause

vapier@, could you help to triage? So far only saw it once.