> The issue here is copy.deepcopy will raise an exception whenever it
> encounters a generator. We would like to do better here.
> Unfortunately, using itertools.tee is not a solution here because it
> does not preserve the type of the object.

Indeed, itertools.tee is not a general solution for copy.deepcopy, but
it's a good solution to *avoid* calling copy.deepcopy when you simply
want to "fork" a generator.

IMHO supporting live generators (and therefore frame objects) in
copy.deepcopy would be a waste of effort.