use static module variable under building Python with --with-experimental-isolated-subinterpreters cause crash.
compiler_mod(struct compiler *c, mod_ty mod)
{
    PyCodeObject *co;
    int addNone = 1;
    static PyObject *module;
    if (!module) {
        module = PyUnicode_InternFromString("<module>");
        if (!module)
            return NULL;
    }
...
}