Py3.7 two tests failing with _impl.MismatchError

The following tests are failing for Py3.7:

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FAIL: oslo_serialization.tests.test_jsonutils.JSONUtilsTestJson.test_dumps_exception_value
oslo_serialization.tests.test_jsonutils.JSONUtilsTestJson.test_dumps_exception_value
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_StringException: Traceback (most recent call last):
  File "/<<PKGBUILDDIR>>/oslo_serialization/tests/test_jsonutils.py", line 120, in test_dumps_exception_value
    jsonutils.dumps({"a": ValueError("hello")}))
  File "/usr/lib/python3/dist-packages/testtools/testcase.py", line 411, in assertEqual
    self.assertThat(observed, matcher, message)
  File "/usr/lib/python3/dist-packages/testtools/testcase.py", line 498, in assertThat
    raise mismatch_error
testtools.matchers._impl.MismatchError: '{"a": "ValueError(\'hello\',)"}' != '{"a": "ValueError(\'hello\')"}'

======================================================================
FAIL: oslo_serialization.tests.test_jsonutils.ToPrimitiveTestCase.test_exception
oslo_serialization.tests.test_jsonutils.ToPrimitiveTestCase.test_exception
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_StringException: Traceback (most recent call last):
  File "/<<PKGBUILDDIR>>/oslo_serialization/tests/test_jsonutils.py", line 411, in test_exception
    jsonutils.to_primitive(ValueError("an exception")))
  File "/usr/lib/python3/dist-packages/testtools/testcase.py", line 411, in assertEqual
    self.assertThat(observed, matcher, message)
  File "/usr/lib/python3/dist-packages/testtools/testcase.py", line 498, in assertThat
    raise mismatch_error
testtools.matchers._impl.MismatchError: "ValueError('an exception',)" != "ValueError('an exception')"