我正在尝试使用 apt-get 在 ubuntu 14.04 LTS 上安装“libgl1-mesa-dev-lts-vivid”，但我收到以下错误消息：
$ sudo apt-get install libgl1-mesa-dev-lts-vivid
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:
libgl1-mesa-dev-lts-vivid : Depends: mesa-common-dev-lts-vivid (=10.5.9-2ubuntu1~trusty2) but it is not going to be installed
Depends: libgl1-mesa-glx-lts-vivid (= 10.5.9-2ubuntu1~trusty2) but it is not going to be installed
unity-control-center : Depends: libcheese-gtk23 (>= 3.4.0) but it is not going to be installed
Depends: libcheese7 (>= 3.0.1) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
我尝试单独安装每个列出的软件包，而 apt-get 只抱怨 mesa-common-dev-lts-vivid。当我尝试手动安装那个时，我得到：
$ sudo apt-get install mesa-common-dev-lts-vivid
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:
libcheese-gtk23 : Depends: libclutter-gtk-1.0-0 (>= 0.91.8) but it is not going to be installed
Depends: libcogl15 (>= 1.15.8) but it is not going to be installed
libcheese7 : Depends: libclutter-gst-2.0-0 (>= 0.10.0) but it is not going to be installed
Depends: gstreamer1.0-clutter but it is not going to be installed
libclutter-1.0-0 : Depends: libcogl-pango15 (>= 1.15.8) but it is not going to be installed
Depends: libcogl15 (>= 1.15.8) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
我已经运行了 apt-get update 和 upgrade。我在几乎全新安装的 ubuntu 14.04 LTS 上运行，只安装了一些 nvidia 图形驱动程序和另一个图形程序。我还在所有涉及的软件包上运行了 apt-show-versions：
gstreamer1.0-clutter:amd64/trusty 2.0.8-1build1 uptodate
libcheese-gtk23:amd64/trusty 3.10.2-0ubuntu2 uptodate
libcheese7:amd64/trusty 3.10.2-0ubuntu2 uptodate
libclutter-gst-2.0-0:amd64/trusty 2.0.8-1build1 uptodate
libclutter-gtk-1.0-0:amd64/trusty-updates 1.4.4-3ubuntu2.2 uptodate
libcogl-pango15:amd64/trusty 1.16.2-1 uptodate
libcogl15:amd64/trusty 1.16.2-1 uptodate
libgl1-mesa-dev-lts-vivid not installed
libgl1-mesa-glx-lts-vivid:amd64/trusty-updates 10.5.9-2ubuntu1~trusty2 uptodate
mesa-common-dev-lts-vivid not installed
unity-control-center:amd64/trusty-updates 14.04.3+14.04.20140922-0ubuntu1.1 uptodate
它们似乎都是安装的有效版本