I'm having the same problem as Arren, but just in case anyone is trying to build php into Apache as a static module, there's a bug in the configure script. (someone else found it, but I can't seem to locate their name just now)
You can get past configure bug by finding the apache directory that contains the include directory, creating a src directory there, then moving the include directory into the src directory. On my system it looked like this...
sources files started here:
httpd-2.0.35/include
I moved them here:
httpd-2.0.35/src/include
don't forget to move them back before trying to compile Apache.
Of course, this is all moot until somebody figures out how to get past the make error.
Quintin