- Use ADDON_LIBS instead of PLIBS, as in the other Makefile-s - ADDON_LIBS aka PLIBS are required to link any GRX program in debug mode even if it doesn't call GrSetMode() etc., because utils/dbgprint.c:_GR_debug_printf() calls GrKeyPressed() and GrKeyRead(), which in turn require the input libraries, which directly or indirectly (through their video driver) refer to ADDON_LIBS / PLIBS. Personally I'd like to see these GrKey*() calls removed and have the debug feature independent of the input and video drivers, but other people may need them...