If you compile mbstring as static module, you can workaround this error. It's not very good idea to enable it anyway..

For the mbstring authors: You should decide whether or not to allow external usage of these functions (ie. in other extensions) or disable the building of this extension as shared altogether..
 

And btw. you shouldn't try outsmarting the configure with all those LIBS/CFLAGS you're defining before running configure..

And read the 'configure --help' sometimes. Some configuration options DO NOT SUPPORT 'shared' at all.
(like --with-xpm-dir)

Building anything as shared is pretty much asking for trouble, just build what you need and don't use the shared modules.

What a fast reply!

I have fixed my configure line now, but when I tried to enable readline support I got:

checking for readline in -lreadline... no
configure: error: readline library not found

Gotta continue with this tomorrow.

readline still wasn't found so I had to disable it. I was not able to build zlib as a shared module.

Here's my new configure line:

'./configure' '--prefix=/usr/local/php4' '--sysconfdir=/etc' '--with-apxs2=/usr/sbin/apxs' '--with-layout=GNU' '--with-config-file-path=/etc/httpd/conf' '--with-openssl=shared,/usr' '--enable-magic-quotes' '--disable-rpath' '--enable-force-cgi-redirect' '--disable-debug' '--enable-pic' '--enable-inline-optimization' '--with-zlib' '--without-aspell' '--with-bz2=shared,/usr' '--enable-calendar=shared' '--with-jpeg-dir=shared,/usr' '--with-tiff-dir=shared,/usr' '--with-curl=shared,/usr' '--enable-dba=shared,/usr' '--with-gdbm=shared,/usr' '--with-db3=shared,/usr' '--with-db4=shared,/usr' '--with-cdb=shared,/usr' '--with-flatfile=shared' '--enable-dbx=shared,/usr' '--enable-dio=shared,/usr' '--with-dom=shared,/usr' '--with-dom-xslt=shared,/usr' '--with-dom-exslt=shared,/usr' '--enable-ftp=shared' '--with-gd=shared' '--with-jpeg-dir=shared,/usr' '--with-png-dir=shared,/usr' '--with-ttf=shared,/usr' '--with-freetype-dir=shared,/usr' '--with-t1lib=shared,/usr' '--enable-gd-native-ttf' '--with-gettext=shared,/usr' '--with-gmp=shared,/usr' '--with-imap=shared,/usr' '--with-imap-ssl=shared,/usr' '--with-ldap=shared,/usr' '--with-mcrypt=shared,/usr' '--with-mhash=shared,/usr' '--enable-mime_magic=shared,/usr' '--with-ming=shared,/usr' '--with-mysql=shared,/usr' '--with-unixODBC=shared,/usr' '--with-jpeg-dir=shared,/usr' '--with-png-dir=shared,/usr' '--with-tiff-dir=shared,/usr' '--with-pgsql=shared,/usr' '--with-pspell=shared,/usr' '--with-recode=shared,/usr' '--with-snmp=shared,/usr' '--enable-ucd-snmp-hack' '--enable-sockets=shared' '--with-regex=system' '--enable-sysvmsg=shared' '--enable-sysvsem=shared' '--enable-sysvshm=shared' '--enable-wddx=shared' '--with-xmlrpc=shared,/usr' '--enable-xslt=shared,/usr' '--with-xslt-sablot=shared,/usr' '--enable-yp=shared' '--with-zip=shared,/usr' '--with-xpm-dir=/usr/X11R6/lib/' '--enable-mbregex=shared' '--enable-overload=shared' '--enable-tokenizer=shared' '--enable-ctype=shared' '--enable-mime-magic=shared' '--enable-shared'

I ran make test and let it send the test by e-mail.

Please try using this CVS snapshot:

  http://snaps.php.net/php4-latest.tar.gz
 
For Windows:
 
  http://snaps.php.net/win32/php4-win32-latest.zip

This bug has been fixed in CVS.

In case this was a PHP problem, snapshots of the sources are packaged
every three hours; this change will be in the next snapshot. You can
grab the snapshot at http://snaps.php.net/.
 
In case this was a documentation problem, the fix will show up soon at
http://www.php.net/manual/.

In case this was a PHP.net website problem, the change will show
up on the PHP.net site and on the mirror sites in short time.
 
Thank you for the report, and for helping us make PHP better.