pybind11 DLL load failed while importing

Question

possible lead I am too stupid to understand

I am trying to build a pybind11 module with CMake on Windows:

#include <iostream>
#include <pybind11/pybind11.h>

void say_hello(){
    std::cout << "Hello, from c++!\n";
}

PYBIND11_MODULE(example, m) {
    m.def("say_hello", &say_hello);
}

cmake_minimum_required(VERSION 3.10.0)
project(example VERSION 0.1.0 LANGUAGES C CXX)

find_package(Python COMPONENTS Interpreter Development REQUIRED)
find_package(pybind11 REQUIRED)

pybind11_add_module(example example.cpp)

dumpbin /dependents build/example.cp311-win_amd64.pyd

Dump of file build\example.cp311-win_amd64.pyd

File Type: DLL

  Image has the following dependencies:

    libgcc_s_seh-1.dll
    KERNEL32.dll
    msvcrt.dll
    libstdc++-6.dll
    python311.dll

import example
example.say_hello()

# >>> ImportError: DLL load failed while importing example

What am I doing wrong? In case there is a solution to my problem, how can I make it reliable on other systems?

EDIT: works flawlessly on linux, obv

Answer 1

Adding the following line:

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -static")

in the CMakeLists.txt file currently solves my problem on my Windows machine. The -static flag tells the compiler to link the DLLs statically, meaning directly inside the .pyd binary file.

Most likely I had a problem with those DLLs dependencies...