### Blocking individual packages when using apt

Posted on 01, Mar 2014

I wanted to install  libsoqt4-dev  so I could compile freecad , however this package depends on  qt4-designer  and  qt4-doc  , which together add about 100 MB to the required download. This is not usually a problem, however I was mobile, and suffering from unreliable internet.

## Blocking packages

I feel confident that not having these two packages will not effect the integrity of the  libsoqt4-dev  installation; they can be blocked individually in  /etc/apt/preferences  like this:

Package: qt4-designer
Pin: origin ""
Pin-Priority: -1

Package: qt4-doc
Pin: origin ""
Pin-Priority: -1

Setting the origin to nothing ensures that they cannot be downloaded, and a negative priority means we really will ignore them. Running:

sudo apt-get install libsoqt4-dev

sees the installation to completion without these dependencies and the large (in context) download. There is no need to run  apt-get update  or anything like that.

Configuring a freecad compilation with  CMake  (on Debian) does not complain about missing  libsoqt4  headers. Instead during compilation lots of errors relating to  undefined reference to SoQtViewer  are thrown. Installing  libsoqt4-dev  fixes this.