vscode-python-test-adapter: Test adapter is not discovering dependencies in alternate directories

I am not seeing any tests in the sidebar widget, despite the Python extension recognizing my tests: (The “Run Tests” button works but nothing happens in the test Explorer). I am seeing output in the log:

============================= test session starts =============================
platform win32 -- Python 3.7.0, pytest-3.10.0, py-1.7.0, pluggy-0.8.0
rootdir: v:\Binning Code\nearest_neighbor (working)\root\nested, inifile:
collected 66 items
<Package 'v:\\Binning Code\\nearest_neighbor (working)\\root'>
  <Package 'v:\\Binning Code\\nearest_neighbor (working)\\root\\nested\\bluelight_binning'>
    <Module 'test_utilities.py'>
....

My preferences are "pythonTestExplorer.testFramework": null and "python.unitTest.pyTestEnabled": true and "python.unitTest.unittestEnabled": false. I’d really like to get this working but I’m not sure what else I can try. Any suggestions?