C++ Boost + Python: undefined reference to Py_Dealloc

Question

I'm trying to use the Python module on Boost. However, I'm getting an error that I cannot find what to do with.

It seems a missing switch or something, but I really could not find...

Does anyone have a clue?

Thanks!!!

/usr/include/python3.8/object.h|478|undefined reference to `_Py_Dealloc'|

System data:

Using Code::blocks, Python 3.8, Linux Mint, installed Boost by apt-get

Build log:

g++ -Wall -fexceptions -g -I/usr/lib/x86_64-linux-gnu/ -I/usr/include/python3.8/ -I/home/tavares/Downloads/boost/boost_1_77_0/stage/lib -c /home/tavares/Trabalho/pesquisa/softwares/optpipeline/PyOPY/PyOPI/bark.cpp -o obj/Debug/bark.o
g++ -Wall -fexceptions -g -I/usr/lib/x86_64-linux-gnu/ -I/usr/include/python3.8/ -I/home/tavares/Downloads/boost/boost_1_77_0/stage/lib -c /home/tavares/Trabalho/pesquisa/softwares/optpipeline/PyOPY/PyOPI/main.cpp -o obj/Debug/main.o
g++ -L/usr/lib/x86_64-linux-gnu/ -o bin/Debug/PyOPI obj/Debug/bark.o obj/Debug/main.o  -lboost_program_options -lboost_system -lboost_python38  
/usr/bin/ld: obj/Debug/bark.o: in function `_Py_DECREF':
/usr/include/python3.8/object.h:478: undefined reference to `_Py_Dealloc'
/usr/bin/ld: obj/Debug/bark.o: in function `boost::python::detail::none()':
/usr/local/include/boost/python/detail/none.hpp:16: undefined reference to `_Py_NoneStruct'
/usr/bin/ld: /usr/local/include/boost/python/detail/none.hpp:16: undefined reference to `_Py_NoneStruct'
/usr/bin/ld: obj/Debug/bark.o: in function `boost::python::api::object::object()':
/usr/local/include/boost/python/object_core.hpp:400: undefined reference to `_Py_NoneStruct'
/usr/bin/ld: /usr/lib/x86_64-linux-gnu//libboost_python38.so: undefined reference to `PyExc_ValueError'
/usr/bin/ld: /usr/lib/x86_64-linux-gnu//libboost_python38.so: undefined reference to `PyLong_AsLong'

Answer 1

This is kinda old, but try adding

$(python3.10-config --ldflags --embed)

to the commands at the linking phase.

Your link command becomes something like

g++ -L/usr/lib/x86_64-linux-gnu/ -o bin/Debug/PyOPI obj/Debug/bark.o obj/Debug/main.o  -lboost_program_options -lboost_system -lboost_python38
$(python3.10-config --ldflags --embed)

Hope this helps someone.