Hello, The link from this page: http://www.ros.org/wiki/DevelopersGuide#Code_layout to https://code.ros.org/svn/ros/stacks/ros/trunk/3rdparty/pycrypto/Makefile?view=markup is broken because now pycrypto is a system-level dependency. It would be nice to find another example of how to wrap an external library. Kind regards and a happy new year, Stéphane -- Dr Stéphane Magnenat http://stephane.magnenat.net