BigQuery: Flaky RefreshError: 'invalid_grant: Invalid JWT: No valid verifier found for issuer.'

[bencaine1]

OS: Linux dc32b7e8763a 4.9.0-6-amd64 #1 SMP Debian 4.9.82-1+deb9u3 (2018-03-02) x86_64 x86_64 x86_64 GNU/Linux
Python version: Python 2.7.6
google-cloud-bigquery: 1.5.0

When trying to do a query, we got the following flaky error (retrying solved the problem):

  File "/usr/local/lib/python2.7/dist-packages/google/cloud/bigquery/client.py", line 1232, in query
    query_job._begin(retry=retry)
  File "/usr/local/lib/python2.7/dist-packages/google/cloud/bigquery/job.py", line 543, in _begin
    method='POST', path=path, data=self._build_resource())
  File "/usr/local/lib/python2.7/dist-packages/google/cloud/bigquery/client.py", line 331, in _call_api
    return call()
  File "/usr/local/lib/python2.7/dist-packages/google/api_core/retry.py", line 260, in retry_wrapped_func
    on_error=on_error,
  File "/usr/local/lib/python2.7/dist-packages/google/api_core/retry.py", line 177, in retry_target
    return target()
  File "/usr/local/lib/python2.7/dist-packages/google/cloud/_http.py", line 290, in api_request
    headers=headers, target_object=_target_object)
  File "/usr/local/lib/python2.7/dist-packages/google/cloud/_http.py", line 183, in _make_request
    return self._do_request(method, url, headers, data, target_object)
  File "/usr/local/lib/python2.7/dist-packages/google/cloud/_http.py", line 212, in _do_request
    url=url, method=method, headers=headers, data=data)
  File "/usr/local/lib/python2.7/dist-packages/google/auth/transport/requests.py", line 198, in request
    self._auth_request, method, url, request_headers)
  File "/usr/local/lib/python2.7/dist-packages/google/auth/credentials.py", line 121, in before_request
    self.refresh(request)
  File "/usr/local/lib/python2.7/dist-packages/google/oauth2/service_account.py", line 322, in refresh
    request, self._token_uri, assertion)
  File "/usr/local/lib/python2.7/dist-packages/google/oauth2/_client.py", line 145, in jwt_grant
    response_data = _token_endpoint_request(request, token_uri, body)
  File "/usr/local/lib/python2.7/dist-packages/google/oauth2/_client.py", line 111, in _token_endpoint_request
    _handle_error_response(response_body)
  File "/usr/local/lib/python2.7/dist-packages/google/oauth2/_client.py", line 61, in _handle_error_response
    error_details, response_body)
RefreshError: ('invalid_grant: Invalid JWT: No valid verifier found for issuer.', u'{\n  "error" : "invalid_grant",\n  "error_description" : "Invalid JWT: No valid verifier found for issuer."\n}')

Would it be possible to add RefreshError to the list of retryable exceptions?

[tseaver]

@bencaine1 I think retry of a credentials request should be handled by the google-auth library. Please file the issue against its tracker.