在盒子上折腾qtmediahub的时候，uxlaunch怎么都无法正常启动，查了一下x11的log，发现错误如下：
_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed_XSERVTransMakeAllCOTSServerListeners: server already running
Fatal server error:
Cannot establish any listening sockets - Make sure an X server isn't already running
【解决方法】rm -rf /tmp/.X11-unix