Repro:
machenbach@malumi:~/v8/infra/infra_internal cons2 $ ./test.py test appengine/chromiumdash
(tried at 08:34 CET)

I'm afraid there might be something time-zone-dependent in the test. Yesterday, this didn't occur, now it does, also for older commits. Can't bisect to any recent revision.

Output:
 ======================================================================
ERROR: handlers.test.add_component_stats_test.AddComponentStatsTest.testAddComponentStats_Multi_Components (/usr/local/google/home/machenbach/v8/infra/infra_internal/appengine/chromiumdash/handlers/test/add_component_stats_test.expected/AddComponentStatsTest.testAddComponentStats_Multi_Components.json)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/ENV/local/lib/python2.7/site-packages/expect_tests/pipeline.py", line 398, in process_test
    subresult = subtest.run()
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/ENV/local/lib/python2.7/site-packages/expect_tests/type_definitions.py", line 253, in run
    return self.func_call(context=context)
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/ENV/local/lib/python2.7/site-packages/expect_tests/type_definitions.py", line 168, in __call__
    return f.func(*f.args, **f.kwargs)
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/ENV/local/lib/python2.7/site-packages/expect_tests/unittest_helper.py", line 40, in _RunTestCaseSingle
    return Result(test_method())
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/ENV/local/lib/python2.7/site-packages/mock.py", line 1220, in patched
    return func(*args, **keywargs)
  File "/usr/local/google/home/machenbach/v8/infra/infra_internal/appengine/chromiumdash/handlers/test/add_component_stats_test.py", line 185, in testAddComponentStats_Multi_Components
    self.assertEquals(expected_results, enitity.results)
  File "/usr/lib/python2.7/unittest/case.py", line 515, in assertEqual
    assertion_func(first, second, msg=msg)
  File "/usr/lib/python2.7/unittest/case.py", line 837, in assertDictEqual
    self.fail(self._formatMessage(msg, standardMsg))
  File "/usr/lib/python2.7/unittest/case.py", line 412, in fail
    raise self.failureException(msg)
AssertionError: {'2017-08-30': {'pri_3': 40, 'pri_2': 40, 'pri_01': 40, 'pri_01_slo': 40, 'stale [truncated]... != {u'2017-08-29': {u'pri_3': 40, u'pri_2': 40, u'pri_01': 40, u'release_block': 40 [truncated]...
Diff is 840 characters long. Set self.maxDiff to None to see it.

==== captured logging output ====
LOG:
INFO: Added timezone to memcache: pytz.zoneinfo.2010h.US/Pacific

STDOUT:
(empty)

STDERR:
(empty)