Wait, this is a big deal. Will it work with any package manager or only things that it explicitly supports?
One thing that has become a persistent headache for me with Nix is trying to get reproducible builds with Julia, due to the fact that the package manager doesn't have direct integration with Nix, and `nix build` purposefully restricts network access. I'd happily move to Guix if they have an elegant way to deal with this.