I’ve just updated from pytorch 0.2.0 to 0.3.0 in a clean anaconda environment using conda install pytorch torchvision -c pytorch. After the update, I’m seeing an error that I don’t see in v0.2.0:
Traceback (most recent call last):
  File "./tools/trainval_net.py", line 129, in <module>
    max_iters=args.max_iters)
  File "/home/thomasbalestri/PycharmProjects/tools/../lib/model/train_val.py", line 378, in train_net
    sw.train_model(max_iters)
  File "/home/thomasbalestri/PycharmProjects/tools/../lib/model/train_val.py", line 269, in train_model
    self.net.train_step(blobs, self.optimizer)
  File "/home/thomasbalestri/PycharmProjects/tools/../lib/nets/network.py", line 678, in train_step
    self._losses['total_loss'].backward()
  File "/home/thomasbalestri/anaconda3/envs/pytorch0.3.0_py2/lib/python2.7/site-packages/torch/autograd/variable.py", line 167, in backward
    torch.autograd.backward(self, gradient, retain_graph, create_graph, retain_variables)
  File "/home/thomasbalestri/anaconda3/envs/pytorch0.3.0_py2/lib/python2.7/site-packages/torch/autograd/__init__.py", line 99, in backward
    variables, grad_variables, retain_graph)
RuntimeError: contiguous is not implemented for type UndefinedType

The error appears to be thrown when I call the backward() method on my loss.
type(self._losses['total_loss'])
<class 'torch.autograd.variable.Variable'>

Any idea what would cause this error?