我正在尝试使用Ubuntu 14.10在远程计算机上安装x2go服务器。 这就是我尝试这样做的方式：
apt-add-repository ppa:x2go/stable
apt-get update
apt-get install x2goserver x2goserver-xsession
直到最后一个代码行才一直顺利，并输出：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package x2goserver-xsession is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
Package x2goserver is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package 'x2goserver' has no installation candidate
E: Package 'x2goserver-xsession' has no installation candidate
我只想使用安装在我的个人计算机上的x2goclient来连接远程计算机。
任何人都知道如何解决这个问题？