>>13736GNU people tend to not use github, hate MIT licensed software, and are generally their own club. I haven't heard of the drama of them sabotaging the rest of the GNU project, what's that about?
In short I think there's very little cross pollination but I've heard Guix can use nix packages (but so can any distro, you can install nix the package manager as a standalone thing). I've never heard of using guix packages or modules on nixos or anyone wanting to.
IMO guix fails right off the bat because they are using scheme as a configuration language. While the nix language is technically a turing complete programming language in practice it's more like writing json with some helper functions sprinkled in if you need them. It's a much better tool because it's a domain specific language purpose built to write configs, where as scheme is a general purpose langauge.