libfreetype6-dev：取决于：libfreetype6？
我正在尝试在ubuntu 14.04嵌入式Zynq SoC处理器上安装opencv
linaro@linaro-nano:~$ sudo apt-get update Ign http://ports.ubuntu.com trusty InRelease Ign http://ppa.launchpad.net trusty InRelease Hit http://ports.ubuntu.com trusty Release.gpg Hit http://ppa.launchpad.net trusty Release.gpg Hit http://ports.ubuntu.com trusty Release Hit http://ppa.launchpad.net trusty Release Hit http://ports.ubuntu.com trusty/main Sources Hit http://ppa.launchpad.net trusty/main Sources Hit http://ports.ubuntu.com trusty/universe Sources Hit http://ppa.launchpad.net trusty/main armhf Packages Hit http://ports.ubuntu.com trusty/main armhf Packages Hit http://ppa.launchpad.net trusty/main Translation-en Hit http://ports.ubuntu.com trusty/universe armhf Packages Hit http://ports.ubuntu.com trusty/main Translation-en Hit http://ports.ubuntu.com trusty/universe Translation-en Reading package lists... Done linaro@linaro-nano:~$ sudo apt-get install pkg-config build-essential libopencv-dev Reading package lists... Done Building dependency tree Reading state information... Done build-essential is already the newest version. pkg-config is already the newest version. 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: libopencv-dev : Depends: libopencv-objdetect-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-highgui-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-legacy-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-contrib-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-videostab-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-superres-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libopencv-ocl-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libcv-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libhighgui-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed Depends: libcvaux-dev (= 2.4.8+dfsg1-2ubuntu1) but it is not going to be installed E: Unable to correct problems, you have held broken packages. linaro@linaro-nano:~$ sudo apt-get install libopencv-objdetect-dev libopencv-highgui-dev libopencv-legacy-dev libopencv-contrib-dev libopencv-videostab-dev libopencv-superres-dev libcvaux-dev libhighgui-dev libcv-dev libopencv-ocl-dev pkg-config build-essential libopencv-dev Reading package lists... Done Building dependency tree Reading state information... Done build-essential is already the newest version. pkg-config is already the newest version. 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: libopencv-highgui-dev : Depends: libgtk2.0-dev but it is not going to be installed E: Unable to correct problems, you have held broken packages. linaro@linaro-nano:~$ sudo apt-get install libgtk2.0-dev libopencv-objdetect-dev libopencv-highgui-dev libopencv-legacy-dev libopencv-contrib-dev libopencv-videostab-dev libopencv-superres-dev libcvaux-dev libhighgui-dev libcv-dev libopencv-ocl-dev pkg-config build-essential libopencv-dev Reading package lists... Done Building dependency tree Reading state information... Done build-essential is already the newest version. pkg-config is already the newest version. 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: libgtk2.0-dev : Depends: libpango1.0-dev (>= 1.20) but it is not going to be installed Depends: libcairo2-dev (>= 1.6.4-6.1) but it is not going to be installed E: Unable to correct problems, you have held broken packages. linaro@linaro-nano:~$ sudo apt-get install libcairo2-dev libpango1.0-dev libgtk2.0-dev libopencv-objdetect-dev libopencv-highgui-dev libopencv-legacy-dev libopencv-contrib-dev libopencv-videostab-dev libopencv-superres-dev libcvaux-dev libhighgui-dev libcv-dev libopencv-ocl-dev pkg-config build-essential libopencv-dev Reading package lists... Done Building dependency tree Reading state information... Done build-essential is already the newest version. pkg-config is already the newest version. 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: libcairo2-dev : Depends: libfontconfig1-dev (>= 2.2.95) but it is not going to be installed Depends: libfreetype6-dev (>= 2.1.10) but it is not going to be installed libpango1.0-dev : Depends: libfreetype6-dev but it is not going to be installed Depends: libxft-dev but it is not going to be installed Depends: libfontconfig1-dev (>= 2.10.91) but it is not going to be installed E: Unable to correct problems, you have held broken packages. linaro@linaro-nano:~$ sudo apt-get install libfontconfig1-dev libxft-dev libfreetype6-dev libfontconfig1-dev libcairo2-dev libpango1.0-dev libgtk2.0-dev libopencv-objdetect-dev libopencv-highgui-dev libopencv-legacy-dev libopencv-contrib-dev libopencv-videostab-dev libopencv-superres-dev libcvaux-dev libhighgui-dev libcv-dev libopencv-ocl-dev pkg-config build-essential libopencv-dev Reading package lists... Done Building dependency tree Reading state information... Done build-essential is already the newest version. pkg-config is already the newest version. 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: libfreetype6-dev : Depends: libfreetype6 (= 2.5.2-1ubuntu2) but 2.5.2-1ubuntu2.2 is to be installed E: Unable to correct problems, you have held broken packages. 您要安装的软件包libfreetype6-dev需要特定版本2.5.2-1ubuntu2的软件包2.5.2-1ubuntu2 ，但您似乎安装了稍微更新的软件包。 不幸的是，你要安装的libfreetype6-dev被配置为只接受一个特定版本的libfreetype6而不是那个和更新版本（原因与否？我不知道）。
要解决依赖关系，可以通过强制apt-get安装所请求的版本来降级libfreetype6 ：
sudo apt-get install libfreetype6=2.5.2-1ubuntu2