The source project of this merge request has been removed.
The libinput driver use screen coordinates unit for touchpad scroll events. It's the same unit as for unaccelerated mouse motion events. Libinput suggests in the code of the libinput debug-gui program that these values should be used directly as the number of pixels to scroll. GTK divided this incoming raw value by 10 (for example with wayland it is here) and should therefore be remultiplied by 10 with a scroll_unit of 10.
The issue I try to resolve is #3631 (closed)