Permanently available environments

[Konrad Hinsen <konrad.hinsen@fastmail.net>]

Hi Guix,

I would like to migrate more of my software use to Guix-based
containers, but I haven't yet found a way to handle them that fully
suits my needs. The root issue is the volatility of environments, and I
wonder if I am missing some feature to handle them better. Here is my
current reasoning:

1. Containers can only be generated using "guix shell" or the older
   "guix environment". There is no way to generate a container based
   on a profile. Correct me if I am wrong!

2. I have been using a plain "guix shell" for a while, but my
   environments break too often after a "guix pull" to continue this
   way. Most of my containerized environments contain no
   security-critical software, so I'd be happy not to update them
   very often (or not at all). That would be trivial with profiles,
   but... point 1.

3. There's the –root option to "guix shell" to protect my environment
   from the garbage collector. But there is no way to say "use the
   environment pointed to by that root, no matter when and how it was
   created". I have to specify the packages with respect to the current
   Guix version (last "pull"). So if I want to protect against updates,
   I have to use "guix time-machine" with "guix shell". Which is fine
   in theory.

4. In practice, I often work with a bad or non-existing network
   connection, so I must be sure to have all my packages in the store.
   And if I use "time-machine", I must also keep the required Guix
   version locally available. But there is no option for that in
   "time-machine". The Guix versions it downloads are garbage-collected
   after a while. So I can find myself in the situation of having all
   the packages for my environment in the store, but unable to access
   it without a network connection, because "time-machine" first needs
   to fetch an old Guix version again.

Did I overlook anything?

Cheers,
  Konrad