TestExtDataSources.test_jdbc_data_source fails in some builds

query_test/test_ext_data_sources.py:75: in test_jdbc_data_source
    self.run_test_case('QueryTest/jdbc-data-source', vector, use_db=unique_database)
common/impala_test_suite.py:731: in run_test_case
    self.__verify_exceptions(test_section['CATCH'], str(e), use_db)
common/impala_test_suite.py:551: in __verify_exceptions
    (expected_str, actual_str)
E   AssertionError: Unexpected exception string. Expected: row_regex:.*Caught exception.*(FATAL: password authentication failed for user "UNKNOWN")
E   Not found in actual: ImpalaBeeswaxException: Query aborted:Caught exception while trying to execute query:Cannot create PoolableConnectionFactory (FATAL: role "UNKNOWN" does not exist)