Now I can confirm, applying the patch mentioned above brings my PC back to normal.
Short summary for everyone else who might read this bug report: Download and save patch as patch.diff and run: sudo apt-build install --patch patch.diff libgl1-mesa-dri -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/1915870 Title: gnome session not starting (segfault with r300_dri.so) To manage notifications about this bug go to: https://bugs.launchpad.net/mesa/+bug/1915870/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp