Open
Description
Required prerequisites
- Make sure you've read the documentation. Your issue may be addressed there.
- Search the issue tracker and Discussions to verify that this hasn't already been reported. +1 or comment there if it has.
- Consider asking first in the Gitter chat room or in a Discussion.
Problem description
This issue is similar to #2101, the reported minimal example problem in #2101 is fixed in the latest master because of #3744. However, the below minimal example will produce the error
1
2
3
terminate called after throwing an instance of 'pybind11::error_already_set'
what(): RuntimeError: instance allocation failed: new instance has no pybind11-registered base types
At:
<string>(4): <module>
Aborted (core dumped)
I can reproduce this problem in Ubuntu and macOS.
The real use case is that each gtest TEST block will have its own py::scoped_interpreter, and this bug is preventing me from writing for i in testclass: more than once, but I would like to write for i in testclass: in multiple different TEST blocks.
Reproducible example code
CMakeLists.txt
cmake_minimum_required(VERSION 3.20)
project(pybindsample)
set(pybind11_DIR "/home/jasjuang/install/share/cmake/pybind11")
find_package(pybind11 REQUIRED)
pybind11_add_module(${PROJECT_NAME} pybindsample.cpp)
target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_17)
add_executable(pybindsample_test pybindsample_test.cpp)
target_link_libraries(pybindsample_test pybind11::module pybind11::embed)
pybindsample.cpp
#include "pybind11/pybind11.h"
#include "pybind11/stl.h"
namespace py = pybind11;
class TestClass {
public:
TestClass() = default;
std::vector<int>::iterator begin() noexcept { return vec.begin(); }
std::vector<int>::iterator end() noexcept { return vec.end(); }
private:
std::vector<int> vec = {1, 2, 3};
};
PYBIND11_MODULE(pybindsample, m) {
py::class_<TestClass>(m, "TestClass")
.def(py::init<>())
.def(
"__iter__",
[](TestClass &t) { return py::make_iterator(t.begin(), t.end()); },
py::keep_alive<0, 1>());
}
pybindsample_test.cpp
#include "pybind11/embed.h"
#include "pybind11/pybind11.h"
#include "pybind11/stl.h"
namespace py = pybind11;
int main() {
{
py::scoped_interpreter g;
py::eval<py::eval_statements>("import pybindsample\n"
"testclass=pybindsample.TestClass()\n"
"for i in testclass:\n"
" print(i)\n");
}
{
py::scoped_interpreter g;
py::eval<py::eval_statements>("import pybindsample\n"
"testclass=pybindsample.TestClass()\n"
"for i in testclass:\n"
" print(i)\n");
}
return 0;
}