Swift.org blog: ABI Stability and More

Thanks for this, but I think the main concern from the other thread was the situation of a hypothetical Swift 6 App wanting to deploy to an OS with built-in Swift 5 libraries.

As well as saying that we won't have to bundle the Swift libraries with Apps any more, there doesn't seem to be a clear statement that using cutting-edge language features may restrict deployment options in the future.

I assume Apple will make some kind of reasonable effort to back-port what they can (as happened with ARC), but we don't know for sure. It's really a policy issue for Apple to address with their developer community (rather than a Swift project issue), but lots of people here deploy to Apple platforms so they'd like to know what this will mean in practice.