Seems like there is a problem when adding ngrest-db package on Mac OS X with the MySQL option. looking through the CMakeLists.txt, it seems that CMAKE_REQUIRED_INCLUDE is not set, so check_include_file_cxx(mysql/mysql.h HAS_MYSQL) will only check the XCode Mac OS X SDK, which does not contain mysql.h nor the PostGRES lib required (but it does contain sqlite3.h, so that option works). I think CMAKE_REQUIRED_INCLUDE should be set by default to "/usr/local/include", so that CMake will search that path for the proper header files.