> If a library exists for Rust 1.0, and then a library author releases a new version of the library with Rust 1.1 features, the Rust 1.0 library does not cease to exist. And Cargo supports semantic versioning...
That's true, but it ignores the way modern software unfortunately works. Programmers are lazy, and maintaining multiple development branches takes work, so they will try not to do that if they can get away with it. How many bug fixes will get backported to Rust 1.0.x, or to the 1.0-supporting version of that library? Probably not very many. Most developers will just bump the major version every 6 weeks, because that's easier than worrying about stability.
I think this attitude is far too cynical. Library authors that care about their users don't break backcompat lightly, and they do backport bugfixes. The mantra "programmers are lazy" does not imply that programmers are inherently amateurs.
I think that isn't so much attitude as experience. That said, I will watch post May 15th and hope I am wrong, but I suspect despite the buzz some of the policies will be (broad adoption) language suicide.
I cannot express how amused I am at the silliness of this whole conversation, which is predicated on the absurd premise that users won't want to upgrade their versions of the compiler. What part of the phrase "backwards compatible" is lost on this crowd?
That's true, but it ignores the way modern software unfortunately works. Programmers are lazy, and maintaining multiple development branches takes work, so they will try not to do that if they can get away with it. How many bug fixes will get backported to Rust 1.0.x, or to the 1.0-supporting version of that library? Probably not very many. Most developers will just bump the major version every 6 weeks, because that's easier than worrying about stability.