Mouse Acceleration Profile does nothing

[Pedro Côrte-Real]

As reported in this bug report:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-libinput/+bug/1772189

on my laptop in Ubuntu 18.04 I've had to disable the libinput acceleration profile to get a usable trackpoint. I'm doing that with:

$ xinput --set-prop 'TPPS/2 IBM TrackPoint' 'libinput Accel Profile Enabled' 0, 1

I assumed setting "Flat" in the "Acceleration Profile" setting of the "Mouse" settings in Tweaks would do the same but that setting doesn't seem to do anything. Since the command above only applies to the Xorg session I don't even know how to fix this issue on Wayland.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-tweaks 3.28.1-1
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu May 31 12:07:10 2018
InstallationDate: Installed on 2016-10-27 (580 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
PackageArchitecture: all
SourcePackage: gnome-tweaks
UpgradeStatus: Upgraded to bionic on 2018-05-19 (11 days ago)