message: tf.distribute input_lib: Have _SingleWorkerDatasetIteratorSpec._options to be an empty InputOptions object rather than None for proper serialization.
diff: @@ -32,6 +32,7 @@ from tensorflow.python.data.ops import iterator_ops
  from tensorflow.python.data.ops import multi_device_iterator_ops
  from tensorflow.python.data.ops import optional_ops
  from tensorflow.python.distribute import device_util
  +from tensorflow.python.distribute import distribute_lib
  from tensorflow.python.distribute import distribute_utils
  from tensorflow.python.distribute import distribution_strategy_context
  from tensorflow.python.distribute import input_ops
  @@ -1996,7 +1997,9 @@ class _SingleWorkerDatasetIteratorSpec(type_spec.TypeSpec):
  self._devices = tuple(
  device_util.canonicalize_without_job_and_task(d) for d in devices)
  self._element_spec = element_spec
  - self._options = options
  + # `self._options` intentionally made not `None` for proper serialization.
  + self._options = (options if options is not None else
  + distribute_lib.InputOptions())
  self._canonicalize_devices = canonicalize_devices
  @property
  