Rust has a pretty strict backwards compatibility policy. Generally speaking breaking changes are not allowed, unless they fix a specific vulnerability or other

Rust has a pretty strict backwards compatibility policy. Generally speaking breaking changes are not allowed, unless they fix a specific vulnerability or other critical issue. Language-level breaking changes can be done with the Edition mechanism. Three editions have been released so far, with three years between each of them. Additionally, new releases are frequently tested with a tool called Crater, which basically builds and runs the tests for all publicly available Rust code. This helps massively in upholding backwards compatibility guarantees and in evaluating if a compatibility break is worth it.