操作系统：Ubuntu 14.04 LTS
$ uname -a
Linux egorov 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
我的目标：通过或软件中心安装libass-dev软件包apt-get
问题描述：
当我尝试
$ sudo apt-get install libass-dev
我越来越
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:
libass-dev : Depends: libfreetype6-dev but it is not going to be installed
Depends: libfontconfig1-dev but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
当我尝试“Ubuntu 软件中心”->“libass-dev”->“安装”时出现以下错误：
这不是唯一存在此类问题的软件包。MB 在我的应用程序仓库中出了点问题。
我试过：
sudo apt-get autoclean
sudo dpkg --configure -a
sudo apt-get install -f
sudo apt-get -u dist-upgrade
和一些类似的建议，但都没有任何帮助。