-fdefer-type-errors for Backpack
It would be great if
-fdefer-type-errors worked with Backpack. There are two senses in which it could work:
- When matching signatures, if the instantiating module didn't provide a required function, we could just create one out of thin air so we can continue building.
- When matching signature, if the implementation doesn't match the signature, we instead create a deferred type error.
(2) is more difficult because it basically requires us to solve #12703.