chell-chrome-pfq failed when doing provisioning / autoupdate:

04/03 02:13:44.785 DEBUG|        dev_server:2070| Exception raised on auto_update attempt #2:
 Traceback (most recent call last):
  File "/home/chromeos-test/chromiumos/src/platform/dev/cros_update.py", line 250, in TriggerAU
    chromeos_AU.PostCheckCrOSUpdate()
  File "/home/chromeos-test/chromiumos/chromite/lib/auto_updater.py", line 1173, in PostCheckCrOSUpdate
    'build' % (self.update_version, self.device.hostname))
  File "/home/chromeos-test/chromiumos/chromite/lib/auto_updater.py", line 981, in _VerifyBootExpectations
    'within %d seconds' % (event, self.KERNEL_UPDATE_TIMEOUT))
RootfsUpdateError: After update and reboot, Chrome failed to reach login screen within 120 seconds


It seems that chell-release is also failing with similar reason:
https://uberchromegw.corp.google.com/i/chromeos/builders/chell-release

04/03 13:27:30.167 DEBUG|        dev_server:2070| Exception raised on auto_update attempt #1:
 Traceback (most recent call last):
  File "/home/chromeos-test/chromiumos/src/platform/dev/cros_update.py", line 250, in TriggerAU
    chromeos_AU.PostCheckCrOSUpdate()
  File "/home/chromeos-test/chromiumos/chromite/lib/auto_updater.py", line 1173, in PostCheckCrOSUpdate
    'build' % (self.update_version, self.device.hostname))
  File "/home/chromeos-test/chromiumos/chromite/lib/auto_updater.py", line 960, in _VerifyBootExpectations
    raise RootfsUpdateError(rollback_message)
RootfsUpdateError: Build chell-release/R59-9428.0.0 failed to boot on chromeos4-row12-rack10-host1; system rolled back to previous build
04/03 13:27:30.169 DEBUG|        dev_server:2076| Please see error details in log /usr/local/autotest/results/hosts/chromeos4-row12-rack10-host1/91897-provision/20170304131624/autoupdate_logs/CrOS_update_chromeos4-row12-rack10-host1_22861.log
04/03 13:27:50.280 DEBUG|        dev_server:2096| AU failed, trying IP instead of hostname: 100.115.203.93

chell-chrome-pfq is going to block master-chromium-pfq on this Wednesday or Thursday if this is continue failing :(


Not sure if this is related, but the following error shows in CrOS_update_*_*.log
[03/Apr/2017:16:36:29] CROS_UPDATE_PROGRESS chromite cannot be imported: ImportError('No module named chromite.lib',)