I noticed that PyTorch couldn’t find the CUDA installation after upgrading to CUDA 9.1 and checking via torch.cuda.is_available(). However, when I downgraded to CUDA 9.0 it worked all fine though. For the pip installer, on the PyTorch page, I noticed that it says “cu90”:
pip3 install http://download.pytorch.org/whl/cu90/torch-0.3.0.post4-cp36-cp36m-linux_x86_64.whl 

I am just wondering if this really is just a “path” issue regarding CUDA 9.1 or if this intended by design (e.g., breaking changes). Not that I need CUDA 9.1, I am just wondering if this is done on purpose, i.e., that the installer only specifically supports CUDA 9.0 and not the consequent patch version (assuming NVIDIA uses semantic versioning)