Issue description

My application crashes when pybind11::scoped_interpreter is destructed after importing torch.

Reproducible example code

#include <pybind11/embed.h>

int main()
{
  pybind11::scoped_interpreter guard{};
  pybind11::exec("import torch");
  // pybind11::module::import("torch"); // same problem
}

Note that the import itself works like a charm.
In the real code, I am using torch and it does what it is supposed to do.
The crash occurs when guard goes out of scope, i.e., when it is destructed.

I guess it's a double-free issue, however, I can't narrow down the problem in torch, I believe the problem is somewhere deep in its C-implementation. Importing tensorflow, numpy, matplotlib and other modules does not make such trouble.
I already asked in the gitter lobby, but I didn't get an answer.