Reproduction case for microsoft/vscode-python#21705

1. Create a virtual env with the following dependencies

mkvirtualenv pytestbug
pip install pytest
pip install pytest-describe

2. Open the project in VSCode

3. Install/Enable the vscode-python extension (ms-python.python) and set the virtualenv to pytestbug (or whatever you configured above)

4. Discover tests -> You should only see 2 tests instead of 4 (cf. underlying issue linked at the top of the file).