The following packages have unmet dependencies
安装FCITX时候出现问题，以前安装过一次，删除后再装就装不上了

$sudo apt-get install fcitx
Reading package lists... Done
Building dependency tree  
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 fcitx : Depends: fcitx-bin but it is not installable
  Depends: fcitx-modules but it is not installable
  Depends: fcitx-module-x11 but it is not installable
  Depends: fcitx-ui-classic but it is not installable
  Recommends: fcitx-pinyin but it is not installable
  Recommends: fcitx-table-wubi but it is not going to be installed or
  fcitx-table-wbpy but it is not going to be installed
  Recommends: fcitx-config-gtk but it is not going to be installed
  Recommends: fcitx-frontend-gtk2 but it is not installable
  Recommends: fcitx-frontend-gtk3 but it is not installable
  Recommends: fcitx-frontend-qt4 but it is not installable
  Recommends: im-config (>= 0.5) but it is not going to be installed or
  im-switch
E: Unable to correct problems, you have held broken packages.


------解决方案--------------------
升级最新版本的apt，自动解决包依赖。
要不然依赖什么包你先查询aptitude search fcitx-bin*
然后在结果中找出具体版本然后apt-get install fcitx-bin-xxxx