output and log:
https://pantheon.corp.google.com/storage/browser/chromiumos-test-logs/bugfiles/cr/727870/

Probably introduced by https://chromium-review.googlesource.com/c/514402/.

Does it still print the regular info in addition to the error?

Yes. The rest info prints out. 

The error is coming from here: https://chromium.googlesource.com/chromiumos/platform2/+/master/chromeos-config/libcros_config/cros_config.cc#89

sjg@ do you see any problem with silencing those errors, since having the database missing is going to be a common situation?

Another option may be hiding the cros_config calls behind #ifdefs that check a macro set by the ebuild. I usually try to stay away from build-time configuration since it makes testing harder (i.e. you need to test on multiple boards instead of just one), but it seems pretty safe here if it's just adding another prefs path.

For the database yes that's fine. And perhaps we should adjust it so that it doesn't try to get the model from mosys if there is no database?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/d594280d03b697b3d9836d9bcf113f8c82ebcbab

commit d594280d03b697b3d9836d9bcf113f8c82ebcbab
Author: Benjamin Gordon <bmgordon@chromium.org>
Date: Wed May 31 19:38:32 2017

Clean up missing cros-config database errors

Not every model will have a config database for some time to come, so
don't print errors to stderr when the file is missing.

BUG= chromium:727870 
TEST=Installed on link and ran power_supply_info; ran tests for reef.

Change-Id: I3bc9c6a72658ce2c238e535292064ecbc379a74c
Reviewed-on: https://chromium-review.googlesource.com/519523
Commit-Ready: Benjamin Gordon <bmgordon@chromium.org>
Tested-by: Benjamin Gordon <bmgordon@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>

[modify] https://crrev.com/d594280d03b697b3d9836d9bcf113f8c82ebcbab/chromeos-config/libcros_config/cros_config.cc
[modify] https://crrev.com/d594280d03b697b3d9836d9bcf113f8c82ebcbab/power_manager/common/prefs.cc

The fix should be in.  Does this need to be backported to M60?

Merging probably isn't super-important, assuming that this isn't breaking any autotests that happen to run power_supply_info (which I'd like us to stop doing per issue 698386, although dump_power_status will probably print the same error without the fix).

Outside of tests, I think that power_supply_info is only run for feedback reports, where this error seems harmless.

Ok, I'll mark this fixed then.

Just in case people look at a certain type of telemetry failures recently, this is the reason. The error message is:

rc2/telemetry_src/src/tools/perf/run_benchmark --verbose --browser=cros-chrome --output-format=chartjson --output-dir=/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src --remote=chromeos4-row12-rack9-host15 octane'
05/31 05:26:02.179 DEBUG|  telemetry_runner:0285| Error occurred executing.
05/31 05:26:02.180 DEBUG|  telemetry_runner:0291| Completed with exit code: 255.
stdout:[ RUN      ] http://chromium.github.io/octane/index.html?auto=1
Traceback (most recent call last):
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 90, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 296, in RunStory
    self._current_page.Run(self)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/page/__init__.py", line 109, in Run
    shared_state.page_test.DidNavigateToPage(self, current_tab)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/tools/perf/benchmarks/octane.py", line 100, in DidNavigateToPage
    self._power_metric.Start(page, tab)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/tools/perf/metrics/power.py", line 90, in Start
    self._platform.StartMonitoringPower(self._browser)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/core/platform.py", line 268, in StartMonitoringPower
    self._platform_backend.StartMonitoringPower(browser)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/internal/platform/cros_platform_backend.py", line 154, in StartMonitoringPower
    self._powermonitor.StartMonitoringPower(browser)
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/internal/platform/power_monitor/cros_power_monitor.py", line 37, in StartMonitoringPower
    if self._IsOnBatteryPower():
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/internal/platform/power_monitor/cros_power_monitor.py", line 103, in _IsOnBatteryPower
    self._platform.RunCommand(['dump_power_status']))
  File "/home/chromeos-test/images/chell-chrome-pfq/R61-9605.0.0-rc2/telemetry_src/src/third_party/catapult/telemetry/telemetry/internal/platform/cros_platform_backend.py", line 70, in RunCommand
    (str(args), stderr))
IOError: Failed to run: cmd = ['dump_power_status'], stderr = [0531/052542:ERROR:cros_config.cc(89)] Could not run command mosys platform model
[0531/052542:ERROR:prefs.cc(54)] Failed to init CrosConfig database.


[  FAILED  ] http://chromium.github.io/octane/index.html?auto=1 (26917 ms)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ]  http://chromium.github.io/octane/index.html?auto=1

1 FAILED TEST

Is this test code assuming that output on stderr means the command failed? It probably shouldn't.

In any case, if this is causing test failures, I take back what I said earlier about not needing to merge to M60. :-P

+hashimoto for comment 13.

Sorry, my memory is vague about this, but IIRC, in https://codereview.chromium.org/798483004/, I changed CrosPlatformBackend.RunCommand to fail when stderr output is not empty, because before that RunCommand never raises an error no matter if the command execution succeeds or not.
Probably I should have used the command's exit status instead of stderr, but I guess it didn't work because some commands just output stderr on errors but exits with no error status.

FYI: This issue is blocking Chrome roll in M60 release branch due to failure in AFDO:

https://uberchromegw.corp.google.com/i/chromeos_release/builders/samus-chrome-pre-flight-branch%20release-R60-9592.B/builds/5
I saw an error message "Failed to run: cmd = ['dump_power_status']"

Please merge the fix to M60. Thanks!

Approved for M60

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/226c1f96ffb9c6d638a6c7d27092f24518f68d81

commit 226c1f96ffb9c6d638a6c7d27092f24518f68d81
Author: Benjamin Gordon <bmgordon@chromium.org>
Date: Thu Jun 01 17:56:44 2017

Clean up missing cros-config database errors

Not every model will have a config database for some time to come, so
don't print errors to stderr when the file is missing.

BUG= chromium:727870 
TEST=Installed on link and ran power_supply_info; ran tests for reef.

Change-Id: I3bc9c6a72658ce2c238e535292064ecbc379a74c
Reviewed-on: https://chromium-review.googlesource.com/519523
Commit-Ready: Benjamin Gordon <bmgordon@chromium.org>
Tested-by: Benjamin Gordon <bmgordon@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
(cherry picked from commit d594280d03b697b3d9836d9bcf113f8c82ebcbab)
Reviewed-on: https://chromium-review.googlesource.com/521302
Commit-Queue: Benjamin Gordon <bmgordon@chromium.org>
Reviewed-by: Benjamin Gordon <bmgordon@chromium.org>
Trybot-Ready: Benjamin Gordon <bmgordon@chromium.org>

[modify] https://crrev.com/226c1f96ffb9c6d638a6c7d27092f24518f68d81/chromeos-config/libcros_config/cros_config.cc
[modify] https://crrev.com/226c1f96ffb9c6d638a6c7d27092f24518f68d81/power_manager/common/prefs.cc

Verified in Chrome OS 9592.5.0, 60.0.3112.10. 

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

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