I didn't manage to use it enough to get to these issues.

I stopped at the point that I had to keep track of an enourmous build.nix file in all my project directories that did a lot of magic if I wanted to use Nix for Go or JS package management.

I also failed completely to search and install executable packages from npm and other minor things I tried.

I did that after going through the complete Nix tutorial and managing to understand pretty much everything and love it.