[Python-ideas] Adding `Unpicklable` to the `collections` module

[Terry Reedy]

>      > Why not `pickle.Incompatible`? It's not like the ABC has anything

>     pickle.Indigestable?
>
>
> Undigestable surely...

I agree with putting whatever in the pickle module.

If there were ever demand for json.Incompatible or whatever, there we 
have it.

-- 
Terry Jan Reedy