[nindalf]

Could you give an example of a Rust release breaking existing compiling code? The Rust Project goes to great lengths to avoid this. For example, before every release they try to compile every open source Rust codebase with the release candidate compiler.

[steveklabnik]

There have been a few. It often comes down to something that was previously unsound being made an error. There’s been long deprecation periods when this happens.

The fact that it’s hard to even remember that these things have happened is a testament to how rarely it happens and how well the breakage is handled.

[nindalf]

Hey Steve, thanks for the response. I was struggling to remember, which is why I asked.

I suspect folks see the Rust release notes on the HN front page and assume that it must be a blockbuster release with lots of move-fast-break-things to make it there. But it’s actually like “new library API, some const fns, compilation time improvements”.

So then they think “this language is moving waaay too quickly, they need to do LTS versions”. But this is just speculation. That’s why I asked GP. Maybe they’ve actually experienced breakage.

[phaylon]

They're usually edge cases. For example let-chains changed the parsing logic for if-let constructs across all editions.

I expect these to become even less frequent with ever rising amounts of Rust code that isn't on Github.