Unable to open a connection to X

台式机新安装 42.1,但运行 steam 时出现“Unable to open a connection to X”的问题,steam suppport 上是这么解答的
When the Steam client is unable to open a connection to the X Window System it will not be able to run at all. Here are some possible causes of this problem:
Your DISPLAY environment variable is set incorrectly, for example it is set to an empty string. You can check the setting by running ‘echo $DISPLAY’ in a terminal window. Unless you have specifically changed it, it should normally be ‘:0’. If it isn’t and you haven’t changed it you can try and run Steam with the default by running ‘DISPLAY=:0 steam’ in a terminal window. You can also try running simple X programs like xclock to see if they work.
You are running through a remote connection, such as ssh, but you have not enabled X remoting. In the case of ssh you need to use ssh -X to enable X forwarding so that X programs can run over the remote connection.
台式是独立显卡,NV 显卡,已经安装完毕驱动,如下图

好吧,google 在英文论坛上找到答案了
运行 xhost +; steam 就 OK 了,但是字体也太虚了吧
还有每次都得 xhost +; steam,没有 彻底解决

cd ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu
mkdir ~/xcb
mv xcb ~/xcb