我正在运行 Ubuntu 12.04（精确穿山甲），并通过安装xserver-xorg-lts-saucy. 我现在想升级到xserver-xorg-lts-trusty，但是当我尝试时，apt-get install xserver-xorg-lts-trusty我得到了很多未满足的依赖项：
% sudo apt-get install xserver-xorg-lts-trusty
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 …我正在尝试通过运行 Ubuntu 12.04 的 Lenovo ThinkCentre M71e 上的 DVI 输出获得 2560x1440 的显示分辨率以正确运行。计算机具有 VGA 和 DVI 连接器。
当我使用 VGA 连接器时，我的显示器可以达到 2560x1440 的完整分辨率。事实上，这是自动检测为默认分辨率的，我没有配置。唯一的问题是由于模拟连接导致图像出现重影。
此时的输出xrandr如下：
% xrandr
Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 8192 x 8192
VGA1 connected 2560x1440+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
2560x1440 60.0*+
1920x1080 60.0
1680x1050 74.9
1280x1024 75.0 60.0
1440x900 59.9
1152x864 75.0
1280x720 60.0
1024x768 75.1 60.0
800x600 72.2 75.0 60.3 56.2
640x480 75.0 …