Touchpad settings don't show up in GNOME

[rennes]

Hello,
In GNOME the touchpad settings don't show up and the 'Tap to Click' 
function does not work on my laptop.

I found the following tickets regarding the problem:

1) https://bugzilla.gnome.org/show_bug.cgi?id=747956
2) https://lists.debian.org/debian-devel/2016/07/msg00266.html

It looks like a conflict between xf86-input-synaptics and 
xf86-input-libinput.

Workaround,

I've removed xf86-input-synaptics from 'xorg' service and later I 
reconfigure:

'guix system -L /home/jin/guix/ reconfigure os-config-gnome.scm'

Works for now!, any idea how we can establish the order in which xorg 
service loads the driver?