I tried to install php with the following options:

./configure \
--with-mysql=/usr/local \
--with-apxs=/usr/sbin/apxs \
--enable-track-vars=yes \
--enable-trans-sid=yes \
--with-gd=/usr/local \
--with-jpeg-dir=/usr/local \
--enable-debug=no \
--disable-pear \
--enable-ftp=yes \
--enable-calendar=yes \
--with-imap=yes \
--with-zlib=/usr/local \
--enable-magic-quotes=yes \
--enable-bcmath=yes \
--with-mhash=yes \
--enable-dbase=yes \
--with-db3=/usr/local/BerkeleyDB.3.2 \
--enable-filepro=yes \
--enable-fast-install=yes \
--enable-mbstr-enc-trans=yes \
--enable-mbstring=yes \
--enable-c9x-inline=no \
--enable-dmalloc=no \
--enable-exif=no \
--enable-experimental-zts=no \
--enable-maintainer-mode=no \
--enable-shared=yes \
--enable-static=no \
--enable-sysvsem=no \
--enable-sysvshm=no \
--with-system-regex=no \
--with-mod-dav=/usr/libexec/httpd/libdav.so \
--x-libraries=/usr/X11R6 \
--with-xpm-dir=/usr/X11R6 \
--with-gdbm=yes \
--with-readline=yes \
--enable-unified-odbc=no

(This configuration worked with Mac OS X 10.0.4 (Darwin 
1.3.7)

I typed "make".
It said

/bin/sh /setup/php-4.0.6/libtool --silent --mode=link cc  
-I. -I/setup/php-4.0.6/ -I/setup/php-4.0.6/main 
-I/setup/php-4.0.6 -I/usr/include/httpd 
-I/setup/php-4.0.6/Zend -I/usr/local/include 
-I/usr/local/BerkeleyDB.3.2/include 
-I/usr/local/include/mysql 
-I/setup/php-4.0.6/ext/xml/expat/xmltok 
-I/setup/php-4.0.6/ext/xml/expat/xmlparse 
-I/setup/php-4.0.6/TSRM  -traditional-cpp -DDARWIN 
-DUSE_HSREGEX -DUSE_EXPAT -DHARD_SERVER_LIMIT=1024 -DEAPI 
-DSUPPORT_UTF8 -DXML_BYTE_ORDER=21 -g -O2   -o libphp4.la 
-rpath /setup/php-4.0.6/libs -avoid-version 
-L/usr/local/lib -L/usr/local/BerkeleyDB.3.2/lib 
-L/usr/X11R6/lib -L/usr/local/lib/mysql  -R /usr/local/lib 
-R /usr/local/BerkeleyDB.3.2/lib -R /usr/X11R6/lib -R 
/usr/local/lib/mysql stub.lo  Zend/libZend.la 
sapi/apache/libsapi.la main/libmain.la regex/libregex.la 
ext/zlib/libzlib.la ext/bcmath/libbcmath.la 
ext/calendar/libcalendar.la ext/dba/libdba.la 
ext/dbase/libdbase.la ext/filepro/libfilepro.la 
ext/ftp/libftp.la ext/gd/libgd.la ext/imap/libimap.la 
ext/mbstring/libmbstring.la ext/mhash/libmhash.la 
ext/mysql/libmysql.la ext/pcre/libpcre.la 
ext/posix/libposix.la ext/readline/libreadline.la 
ext/session/libsession.la ext/standard/libstandard.la 
ext/xml/libxml.la TSRM/libtsrm.la -lc-client -lreadline 
-lhistory -lmysqlclient -lz -lmhash -lgd -lX11 -lXpm -ljpeg 
-ldb -lgdbm -lz -lm
/setup/php-4.0.6/.libs/libphp4.lax/libZend.al
/setup/php-4.0.6/.libs/libphp4.lax/libsapi.al
/setup/php-4.0.6/.libs/libphp4.lax/libmain.al
/setup/php-4.0.6/.libs/libphp4.lax/libregex.al
/setup/php-4.0.6/.libs/libphp4.lax/libzlib.al
/setup/php-4.0.6/.libs/libphp4.lax/libbcmath.al
/setup/php-4.0.6/.libs/libphp4.lax/libcalendar.al
/setup/php-4.0.6/.libs/libphp4.lax/libdba.al
/setup/php-4.0.6/.libs/libphp4.lax/libdbase.al
/setup/php-4.0.6/.libs/libphp4.lax/libfilepro.al
/setup/php-4.0.6/.libs/libphp4.lax/libftp.al
/setup/php-4.0.6/.libs/libphp4.lax/libgd.al
/setup/php-4.0.6/.libs/libphp4.lax/libimap.al
/setup/php-4.0.6/.libs/libphp4.lax/libmbstring.al
/setup/php-4.0.6/.libs/libphp4.lax/libmhash.al
/setup/php-4.0.6/.libs/libphp4.lax/libmysql.al
/setup/php-4.0.6/.libs/libphp4.lax/libpcre.al
/setup/php-4.0.6/.libs/libphp4.lax/libposix.al
/setup/php-4.0.6/.libs/libphp4.lax/libreadline.al
/setup/php-4.0.6/.libs/libphp4.lax/libsession.al
/setup/php-4.0.6/.libs/libphp4.lax/libstandard.al
/setup/php-4.0.6/.libs/libphp4.lax/libxml.al
/setup/php-4.0.6/.libs/libphp4.lax/libtsrm.al
/usr/bin/ld: -undefined error must be used when 
-twolevel_namespace is in effect
make[1]: *** [libphp4.la] Error 1
make: *** [install-recursive] Error 1

Why can't I install php 4.0.6 ?