Hello Tanguy,

Tanguy Le Carrour <tanguy@bioneland.org> writes:

[...]

> I'm struggling to set the keyboard layout as, apparently,
> slim-service-type is not supposed to be extended as gdm-service-type is.

You can set the keyboard layout directly in the slim-configuration like
this:

--8<---------------cut here---------------start------------->8---
(service slim-service-type
         (slim-configuration
          (xorg-configuration
           (keyboard-layout keyboard-layout))))
--8<---------------cut here---------------end--------------->8---

> I guess it's only a matter of copying (and adapting) the `(extend …)` and
> `(compose …)` blocks from `gdm-service-type` to `slim-service-type`. But it's
> just a guess. I've tried to define `my-slim-service-type` in my system config,
> but failed!

It's a good guess: I tried this a while back and it works, if there is
only one instance of slim-service-type: