Installation/import problem -- 'xfeatures2d module is not available'

[stevenjayfrank]

I've hit a dead end attempting to import Valis following installation. Importing results in an AttributeError: module 'cv2' has no attribute 'xfeatures2d'. This is not a new problem and the most common solution is to install opencv-contrib-python rather than opencv-python. Unfortunately the xfeatures2d seems to be unavailable in any opencv distribution compatible with current (or even recent) version of Python. I've tried installing under Windows 11 (which had even more problems) and Linux. Suggestions appreciated.