tensorflow/models · error · Exception

Model has to be built before number of boxes can be determin

Error message

Model has to be built before number of boxes can be determined.

What it means

Error "Model has to be built before number of boxes can be determined." thrown in tensorflow/models.

Source

Thrown at official/projects/yolo/modeling/heads/yolo_head.py:131

      scale = 2**int(key)
      self._head[key] = nn_blocks.ConvBN(
          bias_initializer=self.bias_init(scale, input_shape[key][-1]),
          **self._conv_config)

  def call(self, inputs):
    outputs = dict()
    for key in self._key_list:
      outputs[key] = self._head[key](inputs[key])
    return outputs

  @property
  def output_depth(self):
    return (self._classes + self._output_extras + 5) * self._boxes_per_level

  @property
  def num_boxes(self):
    if self._min_level is None or self._max_level is None:
      raise Exception(
          'Model has to be built before number of boxes can be determined.')
    return (self._max_level - self._min_level + 1) * self._boxes_per_level

  @property
  def num_heads(self):
    return self._max_level - self._min_level + 1

  def get_config(self):
    config = dict(
        min_level=self._min_level,
        max_level=self._max_level,
        classes=self._classes,
        boxes_per_level=self._boxes_per_level,
        output_extras=self._output_extras,
        **self._base_config)
    return config

  @classmethod

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/projects/yolo/modeling/heads/yolo_head.py:131 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/359e1bc0359ed7ec. Report an issue: GitHub.