message: Pass shape for scalar values
diff: @@ -152,7 +152,7 @@ def make_variable(name,
  collections=collections,
  synchronization=synchronization,
  aggregation=aggregation,
  - shape=variable_shape if variable_shape.rank else None)
  + shape=variable_shape if variable_shape else None)
  def collect_previous_mask(input_tensors):
  