Hi Benoit, I found that on internet. Does it help you or talk to you ? http://www.unix.com/programming/153046-fork-thread-assertion-failed-x11.html Cordialement, Olivier Cruilles Mail: linuxos at ...1896... Le 1 mai 2013 à 17:44, Olivier Cruilles <linuxos at ...1896...> a écrit : > gbx3: xcb_io.c :221 : poll_for_event: L'assertion