When running configure for PHP 4.0.4pl1 on FreeBSD 4.1.1/i386, configure fails to properly detect FreeBSD's builtin zlib support. Zlib version 1.1.3 is preinstalled in /usr/lib/libz.{a,so}, however when configure tries to verify zlib's presence it says "zlib support requires zlib version >= 1.0.9" and terminates. It also complains that it can't find gzgets in -lz.

The exact command line I used was:
./configure --with-apxs --enable-sigchild \
--enable-magic-quotes --enable-bcmath --with-bz2 \
--with-gdbm --with-ndbm --enable-ftp --with-gd=/usr/local \
--with-jpeg-dir=/usr/local --with-xpm-dir=/usr/X11R6 \
--with-ttf --enable-gd-imgstrttf --with-imap \
--with-java=/usr/local/jdk1.1.8 --with-ldap --with-mhash \
--with-mysql=/usr/local --with-iodbc --with-pdflib \
--with-zlib-dir=/usr --with-png-dir=/usr/local \
--with-tiff-dir=/usr/local --with-mm --enable-trans-sid \
--with-zlib=/usr --enable-sockets \
--enable-inline-optimization --enable-memory-limit

Upon removing the --with-zlib flag, php compiles fine and works normally.