And adding another dimension: spawning a sub-shell (environment) or not
(profile).

How is this different from the ephemeral vs. persistent dimension?
Creating an ephemeral package set makes sense only if you spwan a
process in it (not necessarily a shell).

You are right, these are (almost?) the same.

Ephemeral could also be imagined without spawning a some process, but also without registering a "root". But this would not work, since as soon as one runs "guix gc" while such an environment is active, the environment would be destroyed.

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |