[Exim] Build problem on OSX 10.1.4

I get the following error when trying to make exim-4.30 on OSX 10.1.4.
exim-4.24 builds fine, but not 4.30:

[dina:~/Documents/work/exim-4.30] engineer% make

>>> Creating links to source files...
>>> New Makefile installed
>>> Use "make makefile" if you need to force rebuilding of the makefile

/bin/sh ../scripts/Configure-os.h
/bin/sh ../scripts/Configure-os.c
cc -O -no-cpp-precomp -DBIND_8_COMPAT -o buildconfig buildconfig.c
-lresolv
/usr/bin/ld: can't locate file for: -lresolv
make[1]: *** [buildconfig] Error 1
make: *** [go] Error 2


I realize OSX 10.1.x is totally legacy at this point, and I do have a
migration path in mind as soon as I get funding, but I would love to be
able to keep exim up to date on this machine for now.

Thanks for any help you guys can give.