Can't find psychopy.hardware.brainproducts locally when trying to import

When I try to import the psychopy brainproducts module

from psychopy.hardware import brainproducts

he can’t find the module. The reason, being simple, that when I try to install psychopy with pip, it apparently does not pull this module from the git repository, i.e. it is not in my C:…\Anaconda3\Lib\site-packages\psychopy\hardware folder.

The problem is solved if I manually copy the brainproducts module from git and save it in the C:…\Anaconda3\Lib\site-packages\psychopy\hardware folder the way it is supposed to be installed from pip.

Any idea what could be a reason for this?