Found a lot reports via google looking up "XDG_RUNTIME_DIR (/run/user/999) is not owned by us (uid 0), but by uid 999! (This could e.g. happen if you try to connect to a non-root PulseAudio as a root user, over the native protocol. Don't do that.)" (last ubuntu ubiquity message at Oct 3 19:36:03 from syslog line https://launchpadlibrarian.net/500526443/syslog) which could be related
** Attachment added: "/var/log/dmesg" https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/1871268/+attachment/5417212/+files/dmesg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1871268 Title: Installation fails when "Install Third-Party Drivers" is selected To manage notifications about this bug go to: https://bugs.launchpad.net/glibc/+bug/1871268/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
