tensorflow/models · error · ValueError

Activation {} not implemented.

Error message

Activation {} not implemented.

What it means

Error "Activation {} not implemented." thrown in tensorflow/models.

Source

Thrown at official/vision/modeling/backbones/spinenet.py:233

    net = self._build_stem(inputs=inputs)
    input_width = input_specs.shape[2]
    if input_width is None:
      max_stride = max(map(lambda b: b.level, self._block_specs))
      input_width = 2 ** max_stride
    net = self._build_scale_permuted_network(net=net, input_width=input_width)
    endpoints = self._build_endpoints(net=net)

    self._output_specs = {l: endpoints[l].get_shape() for l in endpoints}
    super(SpineNet, self).__init__(inputs=inputs, outputs=endpoints)

  def _set_activation_fn(self, activation):
    if activation == 'relu':
      self._activation_fn = tf.nn.relu
    elif activation == 'swish':
      self._activation_fn = tf.nn.swish
    else:
      raise ValueError('Activation {} not implemented.'.format(activation))

  def _block_group(self,
                   inputs: tf.Tensor,
                   filters: int,
                   strides: int,
                   block_fn_cand: str,
                   block_repeats: int = 1,
                   stochastic_depth_drop_rate: Optional[float] = None,
                   name: str = 'block_group'):
    """Creates one group of blocks for the SpineNet model."""
    block_fn_candidates = {
        'bottleneck': nn_blocks.BottleneckBlock,
        'residual': nn_blocks.ResidualBlock,
    }
    block_fn = block_fn_candidates[block_fn_cand]
    _, _, _, num_filters = inputs.get_shape().as_list()

    if block_fn_cand == 'bottleneck':

View on GitHub (pinned to e006f5f0d5)

Solutions

  1. Use a supported activation such as 'relu' or 'swish' in the SpineNet config.
  2. Check the activation name for typos.

When it happens

Trigger: Thrown at official/vision/modeling/backbones/spinenet.py:233 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/34b198be9a05b381. Report an issue: GitHub.