Different results in release and debug builds on different platform architectures

[fraguada]

Hello! I have an issue I can't seem to figure out. We have a library called rhino3dm that we compile to dotnet, webassembly (emscripten), and python (pybind11). There is a native library called OpenNURBS for which we write binding classes that are exposed to pybind11. Until now this worked ok.

Via github actions we build python wheels for macos, windows, and linux. One of my colleagues noticed an issue with one of our bound types that stores a list of model layers, that it was returning a count of 0 when it should be returning something else.

I dug into it further and tested this across platforms and architectures. The issue does not exist in the native library, it does not exist in macos or windows, or ubuntu. I found that when building a release build on x86_64 architecture inside a the manylinux_2_28_x86_64 docker wheel, I could replicate my colleague's issue. If I build with --debug, this issue does not exist.

I know there are many moving parts to our library, but the bug appears only in our python release builds on manylinux x86_64. Again, our native library does not have this issue on any of the platforms or architectures we target.

So, could there be anything related to building our python release builds with pybind11 on manylinux_2_28_x86_64 that could be causing this?