mtr does not compile on Mac OS X because of resolver headers. When I 
changed two includes in dns.c, it compiled and ran:

-#include <arpa/nameser.h>
+#include <arpa/nameser8_compat.h>

and

-#include <resolv.h>
+#include <resolv8_compat.h>

patch-ab already patches dns.c. And since nameser8_compat.h and
resolv8_compat.h are no good for other systems, I'm not quite sure how to 
have a conditional patch. Does anyone know of any good examples?

Thanks,
John Klos