+4.3BSD
+ If you are running a "virgin" version of 4.3BSD, you'll have
+ a very old resolver and be missing some header files. The
+ header files are simple -- create empty versions and everything
+ will work fine. For the resolver you should really port a new
+ version (4.8.3 or later) of the resolver; 4.9 is available on
+ gatekeeper.DEC.COM in pub/BSD/bind/4.9. If you are really
+ determined to continue to use your old, buggy version (or as
+ a shortcut to get sendmail working -- I'm sure you have the
+ best intentions to port a modern version of BIND), you can
+ copy ../contrib/oldbind.compat.c into src and add
+ oldbind.compat.o to OBJADD in the Makefile.
+