pybind11 crashes (segmentation fault (core dumped)) while importing ONNX python module

I am using pybind11 in my C++ code. When I try to import onnx, my code crashes with Segmentation fault (core dumped). However, if I import onnxruntime, everything is well. Of course both onnx and onnxruntime are installed on my system via pip.

// installed libraries
pip install onnx
pip install onnxruntime

// C++ code
#include <pybind11/embed.h>

namespace py = pybind11;

py::module::import("onnxruntime"); // This is okay
py::module::import("onnx"); // This crashes with segmentation fault

The order of the import lines is irrelevant. Wherever it is, py::module::import("onnx") crashes with segmentation fault. How can I successfully run py::module::import("onnx")?

Answer

I am answering my own question. The cause of the problem was that onnx was not compatible with protobuf version 3.19.0 or higher. Using protobuf between 3.18.1 and 3.12.0 will solve the problem.