Huh… did not notice that. But the folders are just a symlinked together.
Although, Cuda.jl complained about AbstractFFTs which complained about ChainRulesCore which complained about a missing source file with no more info. I’m not sure why I did not notice that before.
Installing ChainRulesCode straight from the repo worked, though. I guess I can close this, but it would be nice to understand what is going on.