MINGW-packages: [vapoursynth] Python can't import `vapoursynth` module and can't initialize VSScript when trying to run `vspipe`

Steps to reproduce:

1. pacman -S mingw-w64-x86_64-vapoursynth
2. vspipe -v
3. Fails with: Failed to initialize VSScript

I’ve been running into some issues when trying to use vapoursynth from this package: mingw-w64-x86_64-vapoursynth. The version I have is 57-2. AFAIK I’m running the latest packages for its dependencies, of which Python is 3.9.7 (I think that’s the most relevant dependency at least).

vapoursynth consists of two things: a Python module vapoursynth and the command-line tool vspipe. This is what I get when using them:

$ python
Python 3.9.7 (default, Nov 21 2021, 22:02:56)  [GCC 11.2.0 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import vapoursynth
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'vapoursynth'

and

$ vspipe -v → Failed to initialize VSScript

The VapourSynth documentation points to it being caused by the PYTHONPATH being incorrectly configured. However, I can see that these paths look OK because sys.path reports this:

$ python
Python 3.9.7 (default, Nov 21 2021, 22:02:56)  [GCC 11.2.0 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> print('\n'.join(sys.path))
C:/msys64/mingw64/lib/python39.zip
C:/msys64/mingw64/lib/python3.9
C:/msys64/mingw64/lib/python3.9/lib-dynload
C:/msys64/home/Erik
C:/msys64/mingw64/lib/python3.9/site-packages

and in C:/msys64/mingw64/lib/python3.9/site-packages I can see vapoursynth.dll. So it must be something more complicated than just the Python path being incorrect. I’ll also ask in the vapoursynth repo. about this, but it sounds like there is something funky going on…