Panic in embedding python code in c++ using pybind11

[singhanubhav2000]

I have a problem where the code is panicing when I am making python call from C++.
the python snippet is

import utils
import TplatPythonInterface


       class TplatPyModule:
            def __init__(self):
                pass

            def connect(self, tplatEndpointInfo):
                self.cls = utils.getClassByName(tplatEndpointInfo.plugin_path,
                                                tplatEndpointInfo.sub_plugin,
                                                tplatEndpointInfo.application)
                self.cls.connect(tplatEndpointInfo.endpoint_ip, tplatEndpointInfo.blob)

Here is binding code

#include "embed.h"
#include "stl_bind.h"
#include "tplat_py_wrapper.h"
#include "sma_interface.h"
namespace py = pybind11;

Here epInfo_(of type tplatEndpointInfo*) is defined in the base class smaTplatInterface,

class __attribute__((visibility("hidden"))) tplatPyWrapper :
public smaTplatInterface
{
        static pybind11::module module_;
        pybind11::object pyModule_;     <-- Pointer to python class
        static pybind11::object import(const std::string& module,
                                       const std::string& path,
                                       pybind11::object& globals);
public:
        static void initialize();
        static void finalize();
        tplatPyWrapper(tplatEndpointInfo* epInfo);
        ~tplatPyWrapper() {}

        SmaStatus connect();
};

py::module tplatPyWrapper::module_;

PYBIND11_MAKE_OPAQUE(tplatEndpointInfo);

PYBIND11_EMBEDDED_MODULE(TplatPythonInterface, m) {
        m.doc() = "Thirdplatform framework to python binding";
        py::class_<tplatEndpointInfo>(m, "TplatEndpointInfo", py::call_guard<tplatEndpointInfo>())
                .def(py::init<>(), py::return_value_policy::reference_internal)
                .def_readwrite("application", &tplatEndpointInfo::application_,
                               py::return_value_policy::reference_internal)
                .def_readwrite("endpoint_path", &tplatEndpointInfo::endpoint_path_,
                               py::return_value_policy::reference_internal)
                .def_readwrite("endpoint_ip", &tplatEndpointInfo::endpoint_ip_,
                               py::return_value_policy::reference_internal)
                .def_readwrite("sub_plugin", &tplatEndpointInfo::sub_plugin_,
                               py::return_value_policy::reference_internal)
                .def_readwrite("plugin_path", &tplatEndpointInfo::plugin_path_,
                               py::return_value_policy::reference_internal)
                .def_readwrite("blob", &tplatEndpointInfo::blob_,
                               py::return_value_policy::reference_internal)

The code is panicing at the time when we are trying to call the connect function as defined under.

static void initialize() {
        py::initialize_interpreter();
        py::object main     = py::module::import("__main__");
        py::object globals  = main.attr("__dict__");
        module_ = py::module::import("tplatPyModule");
}

tplatPyWrapper::tplatPyWrapper() {
                auto tplatPyModuleClass = module_.attr("TplatPyModule");
                pyModule_ = tplatPyModuleClass();
}

SmaStatus
tplatPyWrapper::connect()
{
        auto connect = pyModule_.attr("connect");
        connect(epInfo_);
        return SMA_OK;
}
initialize();
tplatPyWrapper* tp = new tplatPyWrapper(epInfo_);
tp->connect();

(gdb) bt
#0  0x00007ffff57845f7 in raise () from /lib64/libc.so.6
#1  0x00007ffff5785ce8 in abort () from /lib64/libc.so.6
#2  0x00007ffff60889d5 in __gnu_cxx::__verbose_terminate_handler() () from /lib64/libstdc++.so.6
#3  0x00007ffff6086946 in ?? () from /lib64/libstdc++.so.6
#4  0x00007ffff6086973 in std::terminate() () from /lib64/libstdc++.so.6
#5  0x00007ffff6086b93 in __cxa_throw () from /lib64/libstdc++.so.6
#6  0x00000000008f32a3 in pybind11::detail::simple_collector<(pybind11::return_value_policy)1>::call (this=0x7fffef9b4950, ptr=0xdbe690) at ../../../common/pybind11/cast.h:1943
#7  0x00000000008f00ee in pybind11::detail::object_api<pybind11::detail::accessor<pybind11::detail::accessor_policies::str_attr> >::operator()<(pybind11::return_value_policy)1, tplatEndpointInfo_*&> (this=0x7fffef9b4990) at ../../../common/pybind11/cast.h:2096
#8  0x00000000008d97c2 in tplatPyWrapper::connect (this=0x7fffcc01b6c0) at tplat_py_wrapper.cc:130

EDIT (@YannickJadoul): Wrapping code fragments with ``` to try achieving readability.

[singhanubhav2000]

@wjakob , @vanossj , @jagerman Any idea on this panic? Please lemme know if you want me to add more info.

[YannickJadoul]

To be honest: I can't make sense of this. If this is still an issue, please post a clean, minimal and complete example that we can look at (potentially in a GitHub gist!). I'm lacking a lot of context, e.g. when this tp->connect(); is called.

I'm closing this. Reopen with the additional requested information if necessary.