Re: Mysteries of channel configuration during system reconfigure

[Kyle Andrews]

Julien Lepiller <julien@lepiller.eu> writes:

> guix system describe lists channels used to build your system, but
> they can be different from the ones currently known to guix.

That seems consistent with what I have observed.

> Does your /etc/channels.scm list the extra channels?

At this point it does not. I "restored" a backup from my old computer
into my home directory. Now I have several more channels than I had
configured in generation one. Unfortunately, now my shepherd is broken
just like on my old computer.

I wish I understood how to experiment with e.g. virtual machines to
better understand this process. However, there seems to be quite a large
knowledge barrier. I also don't feel comfortable with my current
capabilities exploring the Guix codebase to see what the relevant
procedures are. There is a lot to learn!

> "guix describe" will be more accurate about what channels your current
> guix knows about.

It's not clear to me what "your current guix" even is in my case. Does the 
latest pull define the current guix?

On my old computer guix system describe shows a slightly older revision
of Guix channels than guix describe. Meanwhile, the root user's guix describe 
shows just the one Guix channel with yet another commit.

As a naive user, I'm understandably more scared that my computer will
fail to boot if I upgrade, so I tend to run guix system reconfigure less
frequently than guix pull.

> If you type "type guix" and "which guix", they should agree it's
> ~/.config/guix/current/bin/guix, not something else like
> ~/.guix-profile or ~/.guix-home or even /run/current-system

I had never heard of the type command! I noticed type and which give
different results for "type cd" and "which cd". I also noticed that which --all 
guix shows two lines: the latter being /run/current-system.

I have to admit I'm not still sure what general insight I should be gleaning 
from your statement, however it sounds like it is pretty neat.

> If you reconfigure as the root user, you should pull as the root
> user. If you use sudo, which is recommended, make sure that the above
> works properly with sudo too.

I'm curious to learn more about your rationale for this statement as I
was successful at building a second generation only once I used the "sudo" path 
with my non-root user.

Thanks for your help!