So while I am happy that we're talking about stability in crates, I also would love to see some actionable advice for maintainers on how to approach this beyond just adding clippy warnings. Does anyone have good resources to share?

And isn't not just designing the error type, it's also that not using .unwrap() and .expect() requires to return Result<T, E> instead. Which will be a breaking API change for most libraries that might require some thoughtful redesign.