Re: /gnu/store

[Thiago Jung Bauermann]

Hello,

Giovanni Biscuolo <g@xelera.eu> writes:

>> To look for a the Emacs 28.1 file takes also ages.
>
> What is "the Emacs 28.1 file"?

I assume they mean the Emacs executable.

You can look for the Emacs executable currently present in your Guix
profile by looking into the ~/.guix-profile/bin directory. It's small
enough that you can explore it with a file manager, unlike /gnu/store.
It's also simple to check from a terminal, for example with the command
“ls -l ~/.guix-profile/bin/emacs”.

>> I want to change the command for opening emacs in the starter,now 
>> version 27.2 change into emacs 28. So that the emacs icon in the toolbar 
>> opens Emacs 28. Or is the simplest way deleting the icon and after every 
>> new emacs version creating a new icon?
>
> You cannot change the .desktop files used to start applications
> installed via Guix since they are stored read-only in the store

It's possible to override the system-installed .desktop files by
creating new ones in ~/.local/share/applications.

This can be done more easily with a menu editor such as ‘kmenuedit’ in
KDE. I don't know what the Mate equivalent would be. A quick web search
suggests there are both ‘Alacarte’ and ‘Mozo’ but it looks like neither
of them are packaged in Guix unfortunately.

> It's "just" a matter to refresh your graphical menu an usually we need
> to logout and login (at least on a foreign distro)
>
>> 3. Can somebody explain to me the structure of /gnu/store?
>
> Please read the Guix manual at "8.9 The Store"
>
> AFAIK the store is set read-only **but** in any case /do not/ directly
> write to the store, it is accessed by the guix-daemon via the various
> "guix..." command
>
> use the guix cli (or the great emacs-guix interface [1]) to explore your
> packages (et al)
>
> [...]

Reading the manual section about the store as Giovanni suggested is of
course the best way to learn about the /gnu/store organization, but a
quick explanation about the weird directory and file names there is that
the soup of numbers and letters at the beginning is a random but
deterministic identifier of that particular file or package, and is
based on the source code of the package and the environment needed to
build it. If you change anything at all about the file/package or how it
is produced, then the identifier changes as well. This helps Guix
provide its reproducibility properties.

-- 
Thanks
Thiago