I got the following error when I was trying to modify my existing installation of Apache. Only thing I changed was to add –with-expires to my configure. Here is the error:

libtool: link: cannot find the library `/usr/local/src/httpd-2.2.14/srclib/apr-util/xml/expat/lib/libexpat.la' or unhandled argument `/usr/local/src/httpd-2.2.14/srclib/apr-util/xml/expat/lib/libexpat.la'

I was able to fix this error by adding: --with-expat=builtin

Remember to do make clean or untar again before doing configure. Good luck!