With some debugging/instrumentation being added to the compositor I see that the application starts and right after activation (to display the surface), it stops (the surface is being destroyed – like you'd normally see when the application is closed correctly). 

The mixer application used qtaglextras and I had to convert it back to using 3336a398bb8ae52b74affc00dcd03342592c5fd6 to have a bindingAdress being passed on to the application. 

I'm really sure what to do, or follow up on this, if I don't pass a correct bindingAddress the application starts... sort of, but I do see the 'Mixer' right below the top panel. 

Fyi, the 'conversion' code resides in a topic branch of mine at sandbox/mvlad/agl-compositor. 

CC scottm raquelm