I tried deleting miniconda entirely, reinstalling it, creating a new empty environment (just in case) and installing PyTorch with the command from the website. Unfortunately I ran into the exact same issue, once again.
On the other hand I can successfully compile and run the CUDA samples distributed with version 9.0.176, so CUDA and the nvcc tool seem to be working and configured properly, even though I understand it’s irrelevant for PyTorch.
I will shortly try to compile PyTorch from scratch and report the results.