While Manjaro is slightly more stable than upstream Arch Linux, it’s still possible to bonk a system update.
That’s what happened to me three days ago.
I was able to fix almost all issues except my display manager.
After trying to fix the installation for a few hours, I gave up.
My display manager is not terribly important. I need to login and start my X11 session.
A simple command-line interface is enough for me, I do not need a graphical interface to log into my laptop.
It’s pretty straightforward to install on Manjaro:
pacman -S emptty
After that, enable the display manager with
sudo systemctl enable emptty
emptty works out of the box without fuss. The CLI is not very pretty. But it works, and it hopefully won’t break on my next system update.