> there is a risk that the "_utc" variable can be renamed
> and this will break pickle compatibility.
I think we will still need to maintain _utc global indefinitely to keep the old pickles readable.
On the other hand, it looks like support for qualnames is only available with pickle protocol 4, so I don't see any downside from from storing the full qualname other than an 8-byte increase in the size of the pickle.
I guess my position on this will be +0: I'll accept a patch if someone will submit it, but I am unlikely to do it myself.