share guix and its store between distributions

[Emmanuel Beffara]

Hello Guix,

Is there a way to share Guix and its store between several distributions?

My situation is that I have a Guix system installed as my main system, but I
would like to install another distribution on the same machine (a current
Debian, specifically) and use Guix as a package manager there, in order to
benefit from its ability to create reproducible environments. 

Of course, it works to have the other distribution completely independent,
with its own Guix store. The only thing is to handle Grub correctly to give
access to both distros. But it feels like a significant waste of resources,
since I will end up having many things in both stores.

Moreover, ideally I would like to share home directories between the two
distributions, by mounting the same partition as /home, and still be able to
use `guix home` and `guix shell` in both distributions. By some minimal
tuning, I can make it so that users have the same UIDs and GIDs in both
distributions. But I imagine that using Guix in both distributions can become
problematic if they don't share the store and the state in `/var/guix`, for
instance if they don't share GC roots.

Is there a proper way to make that work? Or is it a bad idea?

-- 
Emmanuel