I configured PHP with the following:

./configure --with-apxs=/www/server/apache/bin/apxs --with-yaz=/www/src/yaz-1.6  --with-sybase=/usr/local/sybase/client --with-xml --enable-ftp --with-gd=/www/src/gd1.2 --disable-pear --with-dbase --enable-libgcc --enable-freetype-4bit-antialias-hack  --with-pdflib=/www/src/pdflib-3.03 --with-tiff-dir=/www/src/tiif-v3.4 --with-png-dir=/www/src/libpng-1.0.9 --enable-sockets --with-zlib-dir=/www/src/zlib-1.1.3 --enable-versioning --enable-libgcc

and all goes well through the make process. However when I got to restart Apache (1.3.09) I get the following error:

Syntax error on line 233 of /www/server/apache/conf/httpd.conf:
Cannot load /www/server/apache/libexec/libphp4.so into server: ld.so.1: /www/server/apache
/bin/httpd: fatal: relocation error: file /www/server/apache/libexec/libphp4.so: symbol hstrerror: referenced symbol not found

When I do an ldd for the libphp4.so I get the following:

ldd libphp4.so
        libpam.so.1 =>   /usr/lib/libpam.so.1
        libdl.so.1 =>    /usr/lib/libdl.so.1
        libnsl.so.1 =>   /usr/lib/libnsl.so.1
        libsocket.so.1 =>        /usr/lib/libsocket.so.1
        libsybdb.so =>   /usr/lib/libsybdb.so
        libresolv.so.2 =>        /usr/lib/libresolv.so.2
        libm.so.1 =>     /usr/lib/libm.so.1
        libc.so.1 =>     /usr/lib/libc.so.1
        libmp.so.2 =>    /usr/lib/libmp.so.2
        /usr/platform/SUNW,Ultra-4/lib/libc_psr.so.1