Possible flake in PortableRunnerTest.test_error_traceback_includes_user_code

'second' not found in 'Traceback (most recent call last):\n  File "/home/jenkins/jenkins-slave/workspace/beam_PreCommit_Python_Cron/src/sdks/python/test-suites/tox/py2/build/srcs/sdks/python/apache_beam/runners/portability/fn_api_runner_test.py", line 640, in test_error_traceback_includes_user_code\n    p | beam.Create([0]) | beam.Map(first)  # pylint: disable=expression-not-assigned\n  File "/home/jenkins/jenkins-slave/workspace/beam_PreCommit_Python_Cron/src/sdks/python/test-suites/tox/py2/build/srcs/sdks/python/apache_beam/pipeline.py", line 436, in __exit__\n    self.run().wait_until_finish()\n  File "/home/jenkins/jenkins-slave/workspace/beam_PreCommit_Python_Cron/src/sdks/python/test-suites/tox/py2/build/srcs/sdks/python/apache_beam/runners/portability/portable_runner.py", line 438, in wait_until_finish\n    self._job_id, self._state, self._last_error_message()))\nRuntimeError: Pipeline job-65bf3005-de82-4a1c-8d78-7185c6f627eb failed in state FAILED: unknown error\n'