cc `agar-config --cflags` -o hello foo.c `agar-config --libs`
In file included from /usr/include/SDL/SDL_stdinc.h:28,
                 from /usr/include/SDL/SDL_main.h:26,
                 from /usr/include/SDL/SDL.h:28,
                 from /usr/local/include/agar/agar/core/core.h:30,
                 from foo.c:1:
/usr/include/SDL/SDL_config.h:59:1: warning: "HAVE_SYS_TYPES_H" redefined
In file included from /usr/local/include/agar/agar/core/core.h:15,
                 from foo.c:1:
/usr/local/include/agar/agar/config/have_sys_types_h.h:2:1: warning: this is the location of the previous definition