I ran into the same problem with a self written libwebkitgtk program, also for the 'antialias' property which is asked in the same path XGetDefault call from cairo-xlib-screen.c .
The segfault seems to always occur in the calls from libcairo2, more precisely cairo-xlib-screen.c function _cairo_xlib_init_screen_font_options (Display *dpy, cairo_xlib_screen_t *info) it's always one of the get_integer_default or get_boolean_default calls. If I write down the values in a successful run (for my system that is cairo_bool_t xft_hinting=1; cairo_bool_t xft_antialias=TRUE; int xft_hintstyle=0; int xft_lcdfilter=1; ) and prevent the calls from happening, the segfault goes away. (I create a patched libcairo2) Anyone else who wants to try this (on oneiric): sudo apt-get source libcairo2 sudo apt-get build-dep libcairo2 cd cairo-1.10.2/ modify src/cairo-xlib-screen.c so that values above are used (line 135) and comment out all 3 function calls for get_integer_default or get_boolean_default. sudo dpkg-buildpackage -rfakeroot -b -nc cd .. sudo dpkg -i libcairo2_1.10.2-6ubuntu3_i386.deb libcairo2-dbg_1.10.2-6ubuntu3_i386.deb libcairo2-dev_1.10.2-6ubuntu3_i386.deb libcairo-gobject2_1.10.2-6ubuntu3_i386.deb libcairo-script-interpreter2_1.10.2-6ubuntu3_i386.deb As to what is the clean fix I'm not sure. Is there some requirement on pthread synchronization that cairo doesn't meet when calling XGetDefault, or is it a regular Xorg bug ? I also noticed /etc/xdg/xfce4/Xft.xrdb allows you to set defaults but that didn't seem to help me (even though I'm running xfce4/xubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/931381 Title: sushi-start crashed with SIGSEGV in __pthread_mutex_lock() To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/overlay-scrollbar/+bug/931381/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs