Message 345988 - Python tracker (original) (raw)

If we reintroduce it, why not put it back at its previous place, to provide ABI compatibility?

I agree. If compatibility matters here, then we should add new elements at the end.

First of all, we longer care about ABI compatibility of PyTypeObject.

Oh? In that case, let's just remove the reserved/deprecated field :)

Second, it is extremely unlikely ...

As a rule, "extremely unlikely" isn't unlikely enough for a product with as much reach as Python has. Even if something only happens to 0.1% of users, that's still thousands of people. You have to be prepared to justify hurting those people - potentially to their faces - to back up ideas like this. (And FWIW, yes, I'm happy to explain to people that their pre-generated Cython code broke because Cython had a bug that has since been fixed.)