How to share profile among machines ?

[Emmanuel Medernach <Emmanuel.Medernach@iphc.cnrs.fr>]

Hello Guix !

How do you share profiles among machines ? For instance 2 users wants to 
have the same profile, user A shares the directory 
/gnu/store/...-profile to user B, user B either get access to it 
directly or from a remote machine with a  "guix copy <profile>", user B 
could now use this profile like this:

  export GUIX_PROFILE="/gnu/store/...-profile"
  source "$GUIX_PROFILE/etc/profile"

But there is a problem: this profile is not listed with

  guix package --list-profiles
  guix gc --list-roots

The problem is that if user A deletes this profile it gets garbage 
collected even if user B still needs to use it.

So the question is: How user B could add an existing 
/gnu/store/...-profile (either existing directory or obtained from a 
guix copy) to the profile and root list ?

Cheers,

Emmanuel