Plugins gui ( drumgizmo specifically


I’m on Ubuntu Studio 14.04
and am running latest Ardour build from sources

I built latest version of DrumGizmo from source
and when I add a Midi track with DrumGizmo as plugin,
dubbleclicking the plugin just gives me a dialog where I cannot configure Drumgizmo.

According to here:
I’m supposed to be able to choose xml files.

As a sidenote,
I noticed somewhere during Ardour 4 that the gui from plugins
switched from a ‘rich’ ui to just plain sliders.

Does anybody know the history behind that ?
Or is it a local configuration that I haven’t enabled ?

Anybody else having this issue ?
Thanks for any help or advice.

Missing library was indeed the issue.

Thank you very much !