How to set open_basedir in httpd.conf when running via FCGI?

[MC]

Hi,

I am going to run several virtual hosts under an Apache with PHP
configured via FcgidWrapper.

How can I set up different open_basedir for each of the virtual hosts?

As far as I found, open_basedir is PHP_INI_ALL so I cannot use user.ini,
as the PHP is launched via FCGI, I could not use php_admin_value in
httpd.conf.

What is the best practise (except having a separate PHP install for each
of the virtual host)?

Thanks.