I tried to install python wrappers for OpenKinect on Ubuntu 12.04, but I can't due this error: $ sudo apt-get install python2.7-dev python2.7-dev : Depends: libexpat1-dev but it is not going to be installed Depends: libssl-dev but it is not going to be installed E: Unable to correct problems, you have held broken packages. Python wrapper requires these dependencies: Cython python-dev (error above) python-numpy how can I install python-dev?