Bug#871933: xsynth-dssi: no Gui for plugin after loading

[Olivier Humbert]

Hi.

Today, I made a rebuild of the 0.9.4-2 package on a Debian Stretch.

This is strange because the 0.9.4-2 binary package (amd64) from the 
Debian repository works fine here (GUI displayed), but if I make a 
rebuild of this very package (without changing anything), the GUI isn't 
displayed.

I hope the more-than-me knowledgeable people will find what's wrong here 
since I'm very puzzled myself and don't know who/where to investigate.

HTH,
Olivier