In attempting to build pkgsrc ttcp on my OS X box, I ran into this issue:
===> Building for ttcp-1.12
cc -pipe -g  -Werror  -no-cpp-precomp -c ttcp.c
ttcp.c: In function `main':
ttcp.c:155: `in_addr_t' undeclared (first use in this function)

I have succesly built ttcp previously, but this was around the first 
quarter of last year.  I attempted this build using the latest pkgsrc 
(or close to the latest).  I'm using OS X.1.5.
-- 
Randy

OS X - UNIX for the rest of us
NetBSD - Catch the Power!