I use the first version. There seems now it always downgrades pytorch if I also include torchvision. nightly torchvision seems to be depending on an older version of nightly torch, also the stable torchvision raises an error when I try it with the nightly pytorch.
If I use conda update to update the nightly I get:
Updating pytorch is constricted by

torchvision -> requires pytorch==1.3.0.dev20190917

So I will have to remove torchvision first, and then I can only install the stable torchvision (which does not work against nightly pytorch)