The fact that you see guix downloading mariadb is probably due to “inputs bloat” you may never be able to get rid of it without an upstream fix or providing your own implementation of some upstream package/service. 4 to 6 hours is a lot, do you use substitutes?

If you want to reduce the bloatedness of your operating-system record, look into %desktop-services or %base-services (depending on which one you are overriding) and delete/replace what you will with modify-services.

Here are my configurations.

Assuming that you are using substitutes, I recommend to try waiting a day or two between a guix pull and reconfiguring your system. Unless you have an absurdly slow internet connection, it sounds like your guix is falling back to building some packages due to the substitute servers not having the freshest packages built yet, which can happen often if you reconfigure immediately after pulling.

Can you share your config? Have you enabled substitutes (see here)?

You can look at mine here (it’s pretty small): https://codeberg.org/mrh/dotfiles/src/branch/trunk/guix/system-config.scm

That’s my personal config so you probably don’t wanna copy it verbatim, but it should show you how to do a minimal setup.

I don’t use gnome, but to have gnome just add (service gnome-desktop-service-type) to the services field, and replace %base-services with %desktop-services. It might complain that you have some duplicates after that last step (since I add e.g. elogind service myself, but %desktop-services already has it), but when it does just do exactly what you’d expect and remove the duplicate service. See here for more info.

I also have a few things in there from the nonguix channel, including setting up their substitue server, so be aware of that when copying things.

My config also is setup with an encrypted drive and a swap partition. Again just take the things which make sense and ask about any specific questions you have.

Also note that you should generally install most packages, like kakoune, at the user level, not the system level.

Finally I would recommend joining the IRC channel at #guix on libera.chat. It is very active and people there are always answering questions.