Error page:https://pantheon.corp.google.com/errors/CJ6njZTF_7uVkgE?time=P30D&project=findit-for-me

Stack trace:
AssertionError: Cannot get WfSwarmingTask entity chromium.chromiumos/linux-chromeos-rel/9126/mash_browser_tests.
at GetConsistentFailuresWhenAllTasksComplete (/base/data/home/apps/s~findit-for-me/waterfall-backend:15890-9f10468.410251899267388539/services/test_failure/test_swarming.py:322)
at CallbackImpl (/base/data/home/apps/s~findit-for-me/waterfall-backend:15890-9f10468.410251899267388539/pipelines/test_failure/collect_swarming_task_results_pipeline.py:69)


Failed analysis:
https://findit-for-me.appspot.com/waterfall/failure?url=https://luci-milo.appspot.com/buildbot/chromium.chromiumos/linux-chromeos-rel/9126