I've updated packages (and installed unity-dbg) from ppa with debug symbols, then reboot. The backtrace is attached.
** Attachment added: "gdb-compiz-v3.txt" https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1451613/+attachment/4407575/+files/gdb-compiz-v3.txt -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1451613 Title: Unity/compiz crashes when locking screen To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/1451613/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs