>> 	This is because I need to provide non-IPv6 build (for 1.4.1, for
>> 	example) and IPv6-ready build (for -current).
>For OSes that don't have IPv6 (pkgsrc runs also on Linux and Solaris),
>this should be handled on source level, i.e. there should be appropriate
>defines available to do this. 
>If that is not available, IPv6-mode should be switched on with the
>USE_IPv6 (or what was it) switch. 

	Yes I did like that, patches.v6 is used only when USE_INET6 is
	defined.  Please take a look at Makefile.

itojun