Here it is workable config.
https://lists.gnu.org/archive/html/help-guix/2019-03/msg00152.html <https://lists.gnu.org/archive/html/help-guix/2019-03/msg00152.html>

Ricardo Wurmus said, there is actual manual in every commit. Here it is how to build html manual from your guix (or use info guix instead)
https://lists.gnu.org/archive/html/help-guix/2019-03/msg00173.html


Apr 3, 2019, 9:11 PM by lutheroto@gmail.com:

> After last week's changes to how xorg configuration works, but I still
> have some problems with the touchpad. Essentially, the extra-config
> seems to have no effect.
>
> 1. The Tapping option does not work.
>
> 2. The HorizontalScrolling option does not work. Strangely, the
> documentation[0] says that "HorizontalScrolling" *disables* horizontal
> scrolling. I've tried it both ways.
>
> 3. The DisableWhileTyping option does not work. This actually never
> worked, even before the change.
>
> I've attached my config.scm file.
>
> [0] > https://www.mankier.com/4/libinput#Configuration_Details <https://www.mankier.com/4/libinput#Configuration_Details>
>
> Luther
>