I believe it would be a good idea to have some kind of mechanic to establish a minimum REST version before building a library in order to avoid compilation problems (more precisely to make the user clear that the problem is with their older version of REST).
http://rest-forum.unizar.es/t/cannot-install-restaxionlib-use-of-undeclare-identifier-metadata/49
Problems like the above could be avoided if we implemented this mechanic, maybe on the CMake files, checking if the output of rest-config --version >= MINIMUM_VERSION?