Argh! Now what with eDirectory-based HTTPS?

So I finally get 'authnz-ldap' running, but when I add the documented
directive 'AuthLDAPAuthoritative On' into my .conf and stop/start Apache2
I get an error -

Invalid Command 'AuthLDAPAuthoritative', perhaps misspelled or dfined by a
module not included in the swerver configuration.

And the service won't startup. If I REM (#) this one directive out the
server restarts just fine.

Immediately following that is another ldap-centric directive that the
server seems to have no problem with, suggesting that the correct modules
are loaded.

AuthLDAPURL ldaps://<server>[context]?uid?sub

And yes, I've re-re-re-spelled and type that directive.

<Sigh>. What a battle this has become.