Unity 和 Ubuntu-desktop 消失了，我无法重新安装它！

Question

我正在运行 Ubuntu 13.04。运行正常升级后，Unity消失（登录后，我有桌面，没有启动abd状态栏，没有破折号等）。

如果我尝试重新安装 ubuntu-desktop，我会得到未满足的依赖项：

vmalep@x220t:/mnt/sda2/home/vmalep$ sudo apt-get install
ubuntu-desktop    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.
ubuntu-desktop : Depends: unity but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Unity 更明确一点：

vmalep@x220t:/mnt/sda2/home/vmalep$ sudo apt-get install unity
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.
unity : Depends: libunity-core-6.0-5 (= 7.0.0daily13.04.18~13.04-0ubuntu1) but it is not going to be installed
  Depends: unity-common (= 7.0.0daily13.04.18~13.04-0ubuntu1) but 7.0.0daily13.05.16ubuntu.unity.experimental.certified-0ubuntu1 is to be installed
  Recommends: gnome-control-center-unity but it is not going to be installed
  Recommends: unity-lens-friends but it is not going to be installed
  Recommends: unity-lens-shopping but it is not going to be installed
  Recommends: indicator-bluetooth but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Answer 1

要安装 unity，首先您必须使用 sypnatic 包管理器一一安装所有推荐。在 sypnatic 包管理器中搜索 gnome-control-center-unity、unity-lens-friends 和所有其他推荐。安装完所有建议后，尝试像以前一样安装 Unity，然后 Unity 就会安装。

Answer 2

输出显示您拥有比 Unity 所依赖的更新的包：

unity : Depends: libunity-core-6.0-5 (= 7.0.0daily13.04.18~13.04-0ubuntu1)  

它很可能是由 ppa 引起的。检查您添加的最新 ppa，然后使用 ppa-purge 将其删除。