Connect Oculus Go to Visual Studio Debugger

Is there a step-by-step guide on how to get Visual Studio connecting to a running Oculus Go Unity app?

I can install / run / view the realtime log with adb with no problem. 

Unity itself can see and connect to the app in the profiler window, however,

Visual studio can't see the running app (in Debug->Attach Unity Debugger) to connect.

Is there something I need to do to make it appear?

Device is connected bu USB, app is built is a dev build with script debugging enabled.  Unity 2017.4.6f1, VS 2017 (15.5.6).