c++ - Python.h not found while building sample application with cmake and pybind11

Question

I want to build simple app with pybind11, pybind is already installed in my Ubuntu system with cmake (and make install). I use this simple cmake file:

cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
project(trt_cpp_loader )
find_package(pybind11 REQUIRED)
add_executable(trt_cpp_loader main.cpp)
set_property(TARGET trt_cpp_loader PROPERTY CXX_STANDARD 11)

This is main.cpp:

#include <iostream>
#include <pybind11/embed.h>
namespace py = pybind11;

using namespace std;
int main(){return 0;}

when I build it, I get:

In file included from /usr/local/include/pybind11/pytypes.h:12:0,
                 from /usr/local/include/pybind11/cast.h:13,
                 from /usr/local/include/pybind11/attr.h:13,
                 from /usr/local/include/pybind11/pybind11.h:44,
                 from /usr/local/include/pybind11/embed.h:12,
                 from /home/stiv/lpr/trt_cpp_loader/main.cpp:2:
/usr/local/include/pybind11/detail/common.h:112:10: fatal error: Python.h: No such file or directory
 #include <Python.h>
          ^~~~~~~~~~
compilation terminated.

how can I fix this problem? (python-dev and python3-dev are already installed, Python.h is available)

Answer 1

You'll want to use the pybind11_add_module command (see https://pybind11.readthedocs.io/en/stable/compiling.html#building-with-cmake) for the default case of creating an extension module.

If the goal is indeed to embed Python in an executable, it is your reponsibility to explicitly add python headers & libraries to the compiler/linker commands in CMake. (see https://pybind11.readthedocs.io/en/stable/compiling.html#embedding-the-python-interpreter on how to do that)