tensorflow/models · error

`true_fn` must be callable.

Error message

`true_fn` must be callable.

What it means

Error "`true_fn` must be callable." thrown in tensorflow/models.

Source

Thrown at official/projects/bigbird/recomputing_dropout.py:46

  If `pred` is a bool or has a constant value, we return either `true_fn()`
  or `false_fn()`, otherwise we use `tf.cond` to dynamically route to both.

  Arguments:
    pred: A scalar determining whether to return the result of `true_fn` or
      `false_fn`.
    true_fn: The callable to be performed if pred is true.
    false_fn: The callable to be performed if pred is false.
    name: Optional name prefix when using `tf.cond`.

  Returns:
    Tensors returned by the call to either `true_fn` or `false_fn`.

  Raises:
    TypeError: If `true_fn` or `false_fn` is not callable.
  """
  if not callable(true_fn):
    raise TypeError('`true_fn` must be callable.')
  if not callable(false_fn):
    raise TypeError('`false_fn` must be callable.')
  pred_value = tf.get_static_value(pred)
  if isinstance(pred, tf.Variable) or pred_value is None:
    return tf.cond(
        pred, true_fn=true_fn, false_fn=false_fn, name=name)
  if pred_value:
    return true_fn()
  else:
    return false_fn()


# See https://www.tensorflow.org/api_docs/python/tf/keras/layers/Dropout.
class RecomputingDropout(tf_keras.layers.Layer):
  """`tf_keras.layers.Dropout` that supports `recompute_grad`."""

  def __init__(self,
               rate,

View on GitHub (pinned to e006f5f0d5)

When it happens

Trigger: Thrown at official/projects/bigbird/recomputing_dropout.py:46 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/44cc6674b1462ca8. Report an issue: GitHub.