如果提示：
The following packages have unmet dependencies:
libx11-dev : Depends: libx11-6 (= 2:1.6.4-3ubuntu0.4) but 2:1.6.4-3ubuntu0.5 is to be installed
Recommends: libx11-doc but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
apt-get purge 会同时清除软件包和软件的配置文件