port OOT to gr3.8: python can't find my module

Testing out a port of an OOT into gr3.8.    hpsdr

I've successfully built/installed the ported OOT into gr3.8, and gnuradio-companion finds it and instantiates into a flowgraph.

It's in the group  hpsdr

However when executing the flowgraph, python throws an error that it cannot import hpsdr.   The OOT install put it into:

  /usr/local/lib/python3/dist-packages/hpsdr

but apparently gnuradio-companion is not looking there.

How do I tell gnuradio-companion where to look for my OOT module?

-- Tom, N5EG