tensorflow/models · error · ValueError

Only 'round_robin' and 'waterfall' algorithms are supported,

Error message

Only 'round_robin' and 'waterfall' algorithms are supported, but got %s

What it means

Error "Only 'round_robin' and 'waterfall' algorithms are supported, but got %s" thrown in tensorflow/models.

Source

Thrown at official/nlp/modeling/layers/text_layers.py:490

          (1) For "round_robin" algorithm, available space is assigned
          one token at a time in a round-robin fashion to the inputs that still
          need some, until the limit is reached. It currently only supports
          one or two segments.
          (2) For "waterfall" algorithm, the allocation of the budget is done
            using a "waterfall" algorithm that allocates quota in a
            left-to-right manner and fills up the buckets until we run out of
            budget. It support arbitrary number of segments.

      **kwargs: standard arguments to `Layer()`.

    Raises:
      ImportError: if importing `tensorflow_text` failed.
    """
    _check_if_tf_text_installed()
    super().__init__(**kwargs)
    self.seq_length = seq_length
    if truncator not in ("round_robin", "waterfall"):
      raise ValueError("Only 'round_robin' and 'waterfall' algorithms are "
                       "supported, but got %s" % truncator)
    self.truncator = truncator
    self._init_token_ids(
        start_of_sequence_id=start_of_sequence_id,
        end_of_segment_id=end_of_segment_id,
        padding_id=padding_id,
        special_tokens_dict=special_tokens_dict)

  def _init_token_ids(
      self, *,
      start_of_sequence_id,
      end_of_segment_id,
      padding_id,
      special_tokens_dict):
    usage = ("Must pass either all of start_of_sequence_id, end_of_segment_id, "
             "padding_id as arguments, or else a special_tokens_dict "
             "with those keys.")
    special_tokens_args = [start_of_sequence_id, end_of_segment_id, padding_id]

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/nlp/modeling/layers/text_layers.py:490 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tensorflow/models@e006f5f0d5 (2026-08-24). Data as JSON: /api/errors/e88c1411f0fffd40. Report an issue: GitHub.