Supported automatic version detection starts from 4.3.0.38 onwards. If you need to detect an earlier version, please create a version.py file in the corresponding cv2/ directory with a single line: ------------->8--cut-here--8<----------- opencv_version = "x.y.z.p" ------------->8--cut-here--8<----------- where x.y.z.p is your desired version. When installing older OpenCV versions please use --force_version: ck install package --tags=lib,python-package,cv2 --force_version=4.0.0.21 This will skip version detection.