Deprecation of legacy X11 input drivers

Title: Deprecation of legacy X11 input drivers
Author: Piotr Karbowski <slashbeast@gentoo.org>
Posted: 2020-04-03
Revision: 2
News-Item-Format: 2.0
Display-If-Installed: x11-drivers/xf86-input-mouse
Display-If-Installed: x11-drivers/xf86-input-keyboard

The Gentoo X11 Team is announcing the deprecation and future removal of
the legacy X11 input drivers x11-drivers/xf86-input-mouse and
x11-drivers/xf86-input-keyboard. As of 2020-05-01 those input drivers
will be masked for removal.

These drivers have been deprecated for many years, first by
xf86-input-evdev and then by xf86-input-libinput.

The only use for those drivers remain in deployments which intentionally
opt-out of using udev, as both evdev and libinput require udev during
runtime, however given that upstream has already removed the Linux
support from xf86-input-keyboard, future X11 releases will no longer
support xf86-input-keyboard on Linux rendering those installation
infeasible to use without udev.

In order to ensure frictionless upgrade path for future X11 releases, we
have decided to deprecate those drivers that are not in active use by
pretty much any installation of Gentoo.

No action is required from end-users who are already using libinput (or
evdev). To check which driver is in use, one can use

    $ grep 'Using input driver' ~/.local/share/xorg/Xorg.0.log

for the systems running xorg-server as regular user (-suid
+elogind/+systemd) or by running

    # grep 'Using input driver' /var/log/Xorg.0.log

for those running xorg-server as root.

If however neither libinput or evdev is in use, one should append
'libinput' to the INPUT_DEVICES variable inside /etc/portage/make.conf
while removing 'keyboard' and 'mouse' if present, then update @world
with new USE flags

    # emerge -N @world