Binary package hint: mesa-utils
Description of the problem:
Closing glxgears using the top right hand X on its window frame prints an xcb_xlib_lock: Assertion in ~/.xsession-errors and rather more worryingly causes blips in sound output of totem-gstreamer and rhythmbox...
Steps to reproduce:
1. Start
gnome-terminal .
2. From the terminal start
totem '/home/sits/Examples/ubuntu Sax.ogg' &
3. From within the terminal start
glxgears .
4. Close glxgears using the X at the top right hand corner of the window.
Expected result:
glxgears to close. No output other than fps to be on the terminal. Background sound to continue to play uninterrupted.
Actual result:
glxgears closes. Following output is printed on the terminal:
XIO: fatal IO error 22 (Invalid argument) on X server ":0.0"
after 29 requests (29 known processed) with 0 events remaining.
glxgears: xcb_xlib.c:41: xcb_xlib_lock: Assertion `!c->xlib.lock' failed.
Sound is interrupted and "blips".
How reproducible is this problem:
The xlib.lock error is reproducible every time. The sound interruption is reproducible three quarters of the time.
Additional information:
The blip doesn't seem to occur when using xine-ui to play the background sound. The blip is slight and may require several attempts to identify depending on the exact background sound being played at the time.
Version information:
Ubuntu Feisty
mesa-utils 6.5.2-3ubuntu1
which version of libxcb do you have installed? The latest version (1.0-1.1ubuntu2) has a patch which should fix those assertion bugs (in fact, it only skips the locking test).