I've installed precise package[1] and it works fine on Quantal. So this is really a regression.
[1] http://launchpadlibrarian.net/113881100/xserver- xephyr_1.11.4-0ubuntu10.8_amd64.deb -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1079096 Title: Xephyr does not have GLX To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1079096/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
