When I have more time I hope to investigate specifically what is
different in the assembly code - with/without the __noreturn__ change.

On 19/04/2020 08:20, Batuhan Taskaya wrote:
> Batuhan Taskaya <batuhanosmantaskaya@gmail.com> added the comment:
>
> Moving assertion from _PyObject_GC_TRACK to gen_dealloc (just before the _PyObject_GC_TRACK call) results with success (????)
>
>      if (gen->gi_weakreflist != NULL)
>          PyObject_ClearWeakRefs(self);
> -
> +    _PyObject_ASSERT_FROM(self, !_PyObject_GC_IS_TRACKED(self),
> +                          "object already tracked by they garbage collector",
> +                          __FILE__, __LINE__, "_PyObject_GC_TRACK");
>      _PyObject_GC_TRACK(self);
>  
>      if (PyObject_CallFinalizerFromDealloc(self))
>
> ----------
>
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> <https://bugs.python.org/issue40244>
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