Sorry for the delay, but I was able to generate a backtrace as described by Dirk Seidel in comment #7 and comment #8. The backtrace is attached.
** Attachment added: "gdb-X.txt" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1510998/+attachment/4512905/+files/gdb-X.txt -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1510998 Title: Xorg crashes with segfault on 15.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1510998/+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