anchor.diff:      PortMode = case OS of
   		   {unix, darwin} -> false;
   		   {unix, freebsd} -> false;
  +		   {unix, dragonfly} -> false;
   		   % Linux supports this.
   		   {unix, linux} -> true;
   		   {unix, openbsd} -> true;
  
positive.code: 	    PortMode = case OS of
  			   {unix, darwin} -> false;
  			   {unix, freebsd} -> false;
  			   {unix, linux} -> false;
  			   {unix, openbsd} -> true;
  			   {unix, sunos} -> true;
  
negative.code: get_os_wordsize({unix, darwin})  -> get_os_wordsize_with_uname();
  get_os_wordsize({unix, netbsd})  -> get_os_wordsize_with_uname();
  get_os_wordsize({unix, freebsd}) -> get_os_wordsize_with_uname();
  get_os_wordsize({unix, dragonfly}) -> get_os_wordsize_with_uname();
  get_os_wordsize({unix, openbsd}) -> get_os_wordsize_with_uname();
  get_os_wordsize(_)               -> unsupported_os.
  
  