Gnu Röoty <walidslack@gmail.com> writes:

[…]

> Here my config.scm :

[…]

> (service cups-service-type
> (cups-configuration
> (web-interface? #t)
> (extensions
> (list cups-filters hplip))))

This ‘(service cups-service-type …)’ should be inside the ‘(services
(cons* HERE))’.

> (operating-system
>   …
>   (services (cons* (mate-desktop-service)
>                    %desktop-services))
>
>   ;; Allow resolution of '.local' host names with mDNS.
>   (name-service-switch %mdns-host-lookup-nss))

Then don't forget to reconfigure your GuixSD.

Oleg.