[Dovecot] status of antispam plugin for DC 2.x ?

[interfaSys sàrl]

> $ hg clone http://hg.dovecot.org/dovecot-antispam-plugin/
> $ ./autogen.sh
> $ ./configure prefix=/usr
> $ make
> $ make install
> 
> works for me...
> 
> configure checks for the file dovecot-config. If prefix is /usr it
> expects the file under /usr/lib/dovecot/

Doesn't work at all for me.

When running ./configure prefix=/usr I get a
DC_DOVECOT: not found

The path to dovecot-config is this
/usr/lib/dovecot/dovecot-config