src/contrib/isc-dhcp/includes/minires/resolv.h has a 'extern' definition
but it makes an error when linking crunched binary just like this:
dhclient.lo: In function `MRres_nquery':
dhclient.lo(.text+0x2dcce): undefined reference to `__h_errno_set'
dhclient.lo(.text+0x2dd5b): undefined reference to `__h_errno_set'
dhclient.lo: In function `MRres_nquerydomain':
dhclient.lo(.text+0x2de53): undefined reference to `__h_errno_set'
The author understands this will be a problem (see comments in resolv.h).
Murray said that the author will fix this, but as a temporary solution,
modifying the source code and not to use __h_errno_set.
BTW, I'm sorry that previous commitlog in src/sbin/dhclient/Makefile should
read "Found by:" instead of "Confirmed by"; I just found that rev 1.15
has a typo so fixed.
Tested on: ushi.jp.FreeBSD.org with today's 5-current source code.
(belive me, "make release.4" works fine now)