I cannot reproduce the issue on Linux and get the correct nightly binary:
pip install --pre torch torchvision torchaudio --extra-index-url https://download.pytorch.org/whl/nightly/cpu
Looking in indexes: https://pypi.org/simple, https://download.pytorch.org/whl/nightly/cpu
Collecting torch
Downloading https://download.pytorch.org/whl/nightly/cpu/torch-1.12.0.dev20220417%2Bcpu-cp38-cp38-linux_x86_64.whl (173.1 MB)
...
I’m on Ubuntu 20.04 with Python 3.8 in case that matters.