alt Hacker News> when mixing crates from various editions and how changes interact together.
Could you elaborate more on this? It's not obvious to me right now why (for example) Crate A using the 2024 edition and Crate B using the 2015 edition would require both full access to both crates' source beyond the standard lack of a stable ABI.
Because in order to have standard library breaking changes across editions, if those types are exposed in the crate public types, or change their semantics across editions, the compiler has to be able to translate between them when generating code.
See the Rust documentation on what editions are allowed to change, and the advanced migration guide on examples regarding manual code migration.
Not so much what has happened thus far, rather the limitations imposed in what is possible to actually break across editions.