When I start up my program, I create a window and attach an user-controlled transform (PanZoom for example). But I do not create any shader program in that moment. Then the program will raise an exception in gloo/snippet.py, line 601. It seems that id does not like to have a transform but no shader using it.
It seems that Glumpy raises an error, when it could not find a place to "insert" the snippet. So I just commented out the "raise ..." on line 601 and the program works fine.
The attached file should reproduce the error.