message: Clarify the error message a bit. That should hopefully make cases like easier to debug.
diff: @@ -886,8 +886,10 @@ class Tensor(tensor_like.TensorLike):
  __array_priority__ = 100
  def __array__(self):
  - raise NotImplementedError("Cannot convert a symbolic Tensor ({}) to a numpy"
  - " array.".format(self.name))
  + raise NotImplementedError(
  + "Cannot convert a symbolic Tensor ({}) to a numpy array."
  + " This error may indicate that you're trying to pass a Tensor to"
  + " a NumPy call, which is not supported".format(self.name))
  def __len__(self):
  raise TypeError("len is not well defined for symbolic Tensors. ({}) "
  