On Fri, Nov 09, 2012 at 02:04:13PM +0000, ralf@OpenLDAP.org wrote:

Independ of whether the slapo-deref beign configured or not it always returns "Critical extension is unavailable" to the client.

This is because it doesn't call overlay_register_control anywhere in its code. Fix is underway.

The PCACHE_CONTROL_PRIVDB control defined in slapo-pcache seems to suffer the same problem. (though that's still hidden behind LDAP_DEVEL)