install error

What does this mean? make[1]: Entering directory `/home/php-4.0.6' /home/php-4.0.6/build/shtool mkdir -p "/usr/lib/apache" && /usr/sbin/apxs -S LIBEXECDIR="/usr/lib/apache" -i -a -n php4 libs/libphp4.so apxs:Warning: /usr/bin/httpd not found or not executable apxs:Warning: Continuing anyway... apxs:Warning: No shared object support for Apache apxs:Warning: available under your platform. Make sure apxs:Warning: the Apache module mod_so is compiled into apxs:Warning: your server binary `/usr/bin/httpd'. apsx:Warning: Continuing anyway... apxs:Error: Unknown option: S Usage: apxs -g -n <modname> apxs -q <query> ... apxs -c [-o <dsofile>] [-D <name>[=<value>]] [-I <incdir>] [-L <libdir>] [-l <libname>] [-Wc,<flags>] [-Wl,<flags>] <files> ... apxs -i [-a] [-A] [-n <modname>] <dsofile> ... make[1]: *** [install-sapi] Error 1 make[1]: Leaving directory `/home/php-4.0.6' make: *** [install-recursive] Error 1