Created attachment 330133 [details] backtrace I'm getting a segfault in SleepyHead, but it seems to originate from mesa (xcb-mesa-qt-sleepyhead). I noticed this error after being updated with the x11 stable updates a few days ago. That included both libxcb and mesa. Backtrace attached. I note that in glx_query.c:82 that reply=0x0, and that the function just passes that variable unchecked after getting it from xcb in the line before. I don't know if that function is expected to return a null, but perhaps the library needs to check for it, or perhaps the problem is in qt (which I've been struggling to build with symbols).
Created attachment 330135 [details] updated backtrace
Created attachment 330137 [details] correct updated backtrace
Please also open a bug report upstream at https://bugs.freedesktop.org/ and provide the link.
(In reply to comment #3) > Please also open a bug report upstream at https://bugs.freedesktop.org/ and > provide the link. Done: https://bugs.freedesktop.org/show_bug.cgi?id=57372
Created attachment 330158 [details] backtrace -O0
Just a note that I've narrowed this down quite a bit on the upstream bug report. The problem only occurs with xorg-server 1.13.0 - while the segfault is client-side it is triggered by a change in server-side behavior. Versions of client libs or server drivers do not appear to matter.
I'm going to go ahead and NEEDINFO this for now unless there is objection. SleepyHead has moved on and no longer triggers this bug (substantial changes to its qt/opengl code), and xorg has moved along a ways as well. If it comes up again and becomes an issue I'll re-open with more recent details, etc.
