Failure in beam_PostCommit_XVR_Flink

11:42:19 ======================================================================
11:42:19 ERROR: test_row (apache_beam.transforms.sql_test.SqlTransformTest)
11:42:19 ----------------------------------------------------------------------
11:42:19 Traceback (most recent call last):
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/transforms/sql_test.py", line 147, in test_row
11:42:19     | SqlTransform("SELECT a*a as s, LENGTH(b) AS c FROM PCOLLECTION"))
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/pvalue.py", line 141, in __or__
11:42:19     return self.pipeline.apply(ptransform, self)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/pipeline.py", line 655, in apply
11:42:19     pvalueish_result = self.runner.apply(transform, pvalueish, self._options)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/runners/runner.py", line 198, in apply
11:42:19     return m(transform, input, options)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/runners/runner.py", line 228, in apply_PTransform
11:42:19     return transform.expand(input)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/transforms/external.py", line 295, in expand
11:42:19     transform_proto.inputs[tag] = context.pcollections.get_id(pcoll)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/runners/pipeline_context.py", line 92, in get_id
11:42:19     self._id_to_proto[id] = obj.to_runner_api(self._pipeline_context)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/pvalue.py", line 190, in to_runner_api
11:42:19     coder_id=context.coder_id_from_element_type(self.element_type),
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/runners/pipeline_context.py", line 219, in coder_id_from_element_type
11:42:19     return self.coders.get_id(coders.registry.get_coder(element_type))
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/coders/typecoders.py", line 130, in get_coder
11:42:19     return coder.from_type_hint(typehint, self)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/coders/row_coder.py", line 90, in from_type_hint
11:42:19     schema = named_fields_to_schema(type_hint._fields)
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/typehints/schemas.py", line 127, in named_fields_to_schema
11:42:19     for (name, type) in names_and_types
11:42:19   File "/home/jenkins/jenkins-slave/workspace/beam_PostCommit_XVR_Flink/src/sdks/python/apache_beam/typehints/schemas.py", line 157, in typing_to_runner_api
11:42:19     "type 'str' is not supported in python 2. Please use 'unicode' or "
11:42:19 ValueError: type 'str' is not supported in python 2. Please use 'unicode' or 'typing.ByteString' instead to unambiguously indicate if this is a UTF-8 string or a byte array.