Installing pythonocc-core alongside other C++ extensions bpy causes DLL load failures on Windows

[PaulZemke]

Hi everyone,

I have already raised this issue within the BPY community.
https://projects.blender.org/blender/blender/issues/148944#issuecomment-1752928

What is happening is:

1 - blender ships with OpenEXR 3.3.5 as per the VFXPlatform
2 - import bpy loads all of blenders dependencies into memory, this includes the 3.3.5 copy of openexr.dll which is loaded out of [envroot]\Lib\site-packages\bpy\OpenEXR.dll
3 - import OCC.Core.IGESControl runs a long chain of imports that ends up trying to load freetype.dll from [envroot]\myenv\Lib\site-packages\OCC\Core\freetype.dll which is linked against openexr 3.2.x
4 - Freetype.dll needs the following symbol ?readMemoryMapped@IStream@Imf_3_2@@UEAAPEADH@Z
5 - This symbol does not exist in openexr.dll in 3.3.5
6 - This leads to a OS loader error where it refuses to load freetype.dll due to the missing import
7- this error ruins the load of the package and python ends up giving the following error ImportError: DLL load failed while importing _IGESControl: The specified procedure could not be found.

These two packages are just inherently binary incompatible and the core reason things like the VFX platform exist.

Steps to reproduce: Create a clean Python environment (e.g. Conda or venv) Install both packages: python>=3.11,<3.12.a0 conda install -c conda-forge pythonocc-core=7.9.0 pip install bpy==4.4.0

Therefore my Question: is there a possibilty to build pythonocc-core based on OpenEXR 3.3.5 ?
If that's possible, how can i do this with conda or what have i to change before starting the build and compile process.

Hence my question: Is there a way to build pythonocc-core based on the newer version OpenEXR 3.3.5?
If so, how can I do this with conda, or what do I need to change before starting the build and compilation process?

I would greatly appreciate any ideas or comments on this issue.

Best regards Paul