message: Set exit code on sharded backend_test
diff: @@ -1827,6 +1827,6 @@ if __name__ == '__main__':
  print("n: {}, test: {}".format(n, test))
  suite.addTest(test)
  runner = unittest.TextTestRunner()
  - runner.run(suite)
  + exit(not runner.run(suite).wasSuccessful())
  else:
  unittest.main(argv=sys.argv[:1] + remainder, verbosity=args.verbose + 1)
  