ext/socket/getaddrinfo.cに以下のpatchをおねがいします。
	IPv4 only kernelの上でgetaddrinfo(NULL, "ftp", &hints, &res)
	(hints.ai_flags = AI_PASSIVE)としたときにAF_INET6のアドレスが
	返るのをふせぎます。

itojun


? Makefile
Index: getaddrinfo.c
===================================================================
RCS file: /home/cvs/ruby/ext/socket/Attic/getaddrinfo.c,v
retrieving revision 1.1.2.5
diff -c -r1.1.2.5 getaddrinfo.c
*** getaddrinfo.c	1999/05/10 08:22:49	1.1.2.5
--- getaddrinfo.c	1999/05/20 03:43:44
***************
*** 394,405 ****
--- 394,415 ----
  	 */
  	if (hostname == NULL) {
  		struct afd *afd;
+ 		int s;
  
  		for (afd = &afdl[0]; afd->a_af; afd++) {
  			if (!(pai->ai_family == PF_UNSPEC
  			   || pai->ai_family == afd->a_af)) {
  				continue;
  			}
+ 
+ 			/*
+ 			 * filter out AFs that are not supported by the kernel
+ 			 * XXX errno?
+ 			 */
+ 			s = socket(afd->a_af, SOCK_DGRAM, 0);
+ 			if (s < 0)
+ 				continue;
+ 			close(s);
  
  			if (pai->ai_flags & AI_PASSIVE) {
  				GET_AI(cur->ai_next, afd, afd->a_addrany, port);