I'm on x32-stable and was surprised that I got a black screen instead of loginscreen of lightdm displaymanager after upgrading my system.
After some investigation found that its a missing libgtk-3.so.0. It was installed on the system but instead of /usr/lib as it should be in /usr/lib32 directory.
Culprit was gtk3-classic 3.24.12-1. Downgrading solved the problem only partially. (Error in updating icon cache). Switching to fully blown gtk3 (gtk3 1:3.24.12+32+g39e28ab933-1.0) was a workaround. Another workaround could be to copy the contents of /usr/lib32 to /usr/lib. A repacked gtk-classic with corrected paths would be way better
Thank you in advance