[Python-Dev] pickle output not unique

["Martin v. Löwis"]

> I just wanted to point this out.  We‘ll attempt some local workarounds
> here, but it should otherwise be simple to modify pickling to optionally
> turn off this optimization and always generate the same output
> irrespective of the internal reference counts of the objects.

I think there are many other instances where values that compare equal
pickle differently in Python. By relying on this property for hashing,
you are really operating on thin ice.

Regards,
Martin