MINGW-packages: OpenCV Python missing dependency

Hi, when using mingw-w64-opencv with python I got an error message of missing DLL files: $ python -c "import cv2" Traceback (most recent call last): File "<string>", line 1, in <module> ImportError: DLL load failed while importing cv2: Die angegebene Prozedur wurde nicht gefunden.

This happened when installing OpenCV inside a new MSYS2 environment. I did some additional tests and got strange results:

1. Install MSYS2 and install OpenCV -> test failed, see above
2. Build package myself, without any modifications, but do not install it -> test failed (this test would not have failed if any build dependency was needed at runtime too)
3. Install my own build package -> test successful, finally
4. Reinstall prebuild package from server ->test failed again

Also note, that my build package is slightly bigger than the prebuild one (both are version 4.3.0-2). I can not really tell any difference between those packages, just that the prebuild one is not working. Maybe check the build server?