Sharing types across modules and compiler compatibility

[fsodari]

Hello,

I'm curious about the limitations of ABI/compiler compatibility.
I'm working on a project utilizing a "plugin" architecture, where there is a base project and plugin projects will inherit from C++ types from the base project and build modules that interact with the base project. All shared types and plugin modules are nanobind extensions. And I want to deploy manylinux wheels to pypi.org.

I find that I can get everything to work exactly how I want, provided that plugins use the same compiler version as what the base project's wheel was built with. For example, if I build a manylinux_2_28 wheel (gcc13) for the base project, I have to use gcc13 when building a plugin wheel locally, or I have to build and install a matching manylinux_2_28 wheel using cibuildwheel. If the compiler doesn't match, I get "TypeError...incompatible function arguments..." when I try to pass objects between different extensions. I did this comparison using Ubuntu22.04 using the default gcc11 and installing gcc13, and using Ubuntu24.04 with the default gcc13. I'm using python3.12, stable_abi, and nb_static.

The nanobind docs mention gcc/clang compatibility issues, but is this essentially an unsolvable issue due to variations between gcc versions? Or is this a libc++ version issue? Is there any way I can make my project compatible across different versions of gcc or different manylinux images? It would be nice if I didn't need to impose a compiler restriction on plugin developers.

But ultimately, gcc13/ubuntu24 should be easily obtainable for developers, and my project is otherwise accessible by building the base project from source or building plugins with cibuildwheel. So I don't really see this as a big problem. I'm just curious if there's anything different that I can do or if this is just how it is. Thanks.

[wjakob]

nanobind is currently unnecessarily strict. It will be fixed by #788. I am waiting for PR pybind/pybind11#5439 to wrap up so that nanobind can match pybind11's behavior.

[fsodari]

That sounds great! Thanks.