Arch Linux

Description:
If nvidia is upgraded (or installed with a new install of Arch), a no boot situation arises if gdm is used and the line to disable wayland is not set. It took me a while to find this post which allowed installation of nvidia drivers. System is fully up to date. All I did was disable Wayland in gdm and it seems to be functional.
https://bbs.archlinux.org/viewtopic.php?id=238602

Additional info:
* package version(s)
nvidia-lts 1:396.24-4

* config and/or log files etc.
/etc/gdm/custom.conf

add:
WaylandEnable=false
as a post install script if gdm is installed or the boot will hang at 'starting'

Steps to reproduce:
Upgrade or install nvidia or nvidia-lts with pacman.

A clean install boots fine with nouveau. If the nvidia package is added (at least with gdm installed), the boot stalls at 'starting'