How am I meant to open a volume encrypted using both key and keyfile?

[Seswu]

I can encrypt a volume using 'key+keyfile', and this seems to work well enough.
On exit, I am notified that to open the volume, I need to use the 'hmac' plugin.
This plugin does not seem to be available in the package repository (debian), but also I am not sure how to go about adding it from the zuluCrypt site; there does not seem to be a binary package available.
The FAQ does not mention it; man-pages.. does not seem to mention this option either.

I can see the 'hmac' plugin in the plugins directory; it looks like one needs to compile everything from source, somehow including the plugin(s) one wants?
I am not entirely sure how to go about that, if it's needed. Is it?
Also I am not sure how to use the plugin afterwards. It -looks- like it'll affect the gui.