When starting X with x11-base/xorg-server-1.19.1 (current unstable version) and x11-drivers/xf86-input-libinput (current stable version), the X server crashes at startup. I don't have access to the exact error message (I am away from the computer this was happening on) but it boiled down to an unresolved symbol AddEnabledDevices. That symbol was removed in xorg-server-1.19. xf86-input-libinput-0.19 needs it, but 0.20 and above do not. A blocker should be added to prevent other people from having to go through a painful debugging experience to find out why their X server won't start.
Yep, you are right. Thanks for the heads up. Fixed by commit b4f709f6d2f259727f9696991af228de7b3096e5 Author: Matt Turner <mattst88@gentoo.org> Date: Thu Mar 2 20:01:16 2017 -0800 x11-base/xorg-drivers: Add blocker for old versions of xf86-input-libinput.
