bug#33189: Touchpad tap

[Alex Griffin]

If you want to force the libinput driver, it's way easier to just remove 
synaptics from the list of Xorg modules.

    (set-xorg-configuration
     (xorg-configuration
      (keyboard-layout keyboard-layout)
      (modules (filter (lambda (mod)
                         (not (eq? mod xf86-input-synaptics)))
                       %default-xorg-modules))))

Or if you don't want to do that, you can use synclient to configure the 
synaptics driver after it has already loaded. No need to fiddle with X11 config 
files.

It looks like this issue is probably the same as #35450, where Florian has 
identified the cause.

-- 
Alex Griffin