Ubuntu 14.04.5 LTS 安装quantum失败

执行安装命令时apt-get install quantum-server，出错，网络上也找了很久，还没有找到解决办法，请问有没有什么建议。谢谢。
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:
quantum-server : Depends: quantum-common but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

经过 苦心钻研，就在快要放弃时，找到解决办法，分享一下。
使用apt-get安装程序时，报告已安装依赖库的版本高于安装包所需的依赖库指定版本。
首先使用如下命令查看低版本信息
apt-cache showpkg python-sqlalchemy
再安装低版本
aptitude install python-sqlalchemy=0.7.4-1ubuntu0.1
然后再安装quantum-server
apt-get install -y quantum-server

这个包没有，先安装这个包
apt-get install quantum-common