Thank you for your reply. For reference, the last CUDA Toolkit 11.8 release was 1.5 years ago, so it was already outdated when NixOS 23.11 was released. Trying to pin CUDA to 12.4 doesn’t seem to work. I do understand that I am not the only one with CUDA issues though: Tweag+Nix dev update #45. Connor Baker seems to be the person to ask.