build pytorch documentation import error

Question

I am trying to build pytorch's documentation. I insatlled sphinx and readthedocs theme. And ran the commands on the pytorch GitHub page for building the documentation. When I run make singlehtml or any other format, they all give me an import error like this:

Traceback (most recent call last):
File "source/scripts/build_activation_images.py", line 8, in <module>
import torch.nn.modules.activation
ImportError: No module named torch.nn.modules.activation
make: *** [figures] Error 1

I think the script is trying to use python 2 instead of python 3 because on my computer, I have to type python3 and pip3 to use python 3 and the GitHub page used pip.

But I'm not really sure and I don't know how to solve it.