For a few months this year, running “dnf update” caused my display manager to malfunction. It it a terribly annoying problem. In the past, once, my /usr/bin/X was not installed. I don’t know how that happened.
This time, lightdm was not starting due to some error message which is only visible if you turn on logging/debugging and go find the right log.
lightdm gtk:error:gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed
Thankfully, the issue was researchable online although it did take a while and I bounced around different distros’ fora to get to the answer.
For Fedora, the answer simply was:
sudo dnf -y reinstall shared-mime-info
- points to the next two links https://bbs.archlinux.org/viewtopic.php?id=223801
- what actually solved it http://forum.tinycorelinux.net/index.php?topic=4389.0
- same kind of error https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/1627564