我正在使用Ubuntu 11.04，并且正在尝试安装TortoiseHg。我已经从TortoiseHg的网站上应用了PPA，因此apt-get实际上可以找到它。但是，无论何时键入sudo apt-get tortoisehg，我都会得到：
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:
tortoisehg : Depends: mercurial (>= 1.8) but 1.7.5-1ubuntu1 is to be installed
E: Broken packages
我理解这意味着什么：我需要安装Mercurial 1.8。问题是我做不到。如果尝试的话sudo apt-get install mercurial，它表示1.7.5是最新版本，但肯定不是。
那么，我如何说服这件事安装最新版本的Mercurial？
我尝试了此答案中的命令来安装Mercurial，但这没有帮助。它再次表示，Mercurial是最新的。