我在 Ubuntu 16.04 上安装了 KDE Plasma 5.6，一切运行正常。
几天前，我尝试安装新版本的 KDE Plasma（我尝试了提到的临时 ppa这里和其他试验）并且在某种程度上破坏了我的 KDE。
现在我想重新安装 KDE Plasma 5.6，因此尝试首先删除 KDE 的所有痕迹并重新安装它，基本上遵循过去使用的命令：
$ sudo add-apt-repository ppa:kubuntu-ppa/backports
$ sudo apt-get update
$ sudo apt-get dist-upgrade
$ sudo apt-get install kubuntu-desktop
但现在我收到此错误：
The following packages have unmet dependencies:
kubuntu-desktop : Depends: breeze but it is not going to be installed
Depends: dolphin but it is not going to be installed
Depends: kde-cli-tools but it is not going to be installed
Depends: khelpcenter but it is not going to be installed
Depends: kinfocenter but it is not going to be installed
Depends: kwin
Depends: plasma-desktop but it is not going to be installed
Depends: sddm-theme-breeze but it is not going to be installed
Depends: systemsettings but it is not going to be installed
Recommends: akregator but it is not going to be installed
Recommends: apturl-kde but it is not going to be installed
Recommends: bluedevil but it is not going to be installed
Recommends: kaddressbook but it is not going to be installed
Recommends: kate but it is not going to be installed
Recommends: kde-config-sddm but it is not going to be installed
Recommends: kde-telepathy but it is not going to be installed
Recommends: kdeconnect-plasma but it is not going to be installed
Recommends: kmail but it is not going to be installed
Recommends: knotes but it is not going to be installed
Recommends: kontact but it is not going to be installed
Recommends: korganizer but it is not going to be installed
Recommends: kscreen but it is not going to be installed
Recommends: kwin-addons but it is not going to be installed
Recommends: milou but it is not going to be installed
Recommends: plasma-dataengines-addons but it is not going to be installed
Recommends: plasma-discover but it is not going to be installed
Recommends: plasma-nm but it is not going to be installed
Recommends: plasma-pa but it is not going to be installed
Recommends: plasma-runners-addons but it is not going to be installed
Recommends: plasma-wallpapers-addons but it is not going to be installed
Recommends: plasma-widgets-addons but it is not going to be installed
Recommends: print-manager but it is not going to be installed
我能做什么？非常感谢 Vincenzo