diff --git a/content/Rust-1.92.0.md b/content/Rust-1.92.0.md new file mode 100644 index 000000000..e46194e94 --- /dev/null +++ b/content/Rust-1.92.0.md @@ -0,0 +1,116 @@ ++++ +path = "2025/12/11/Rust-1.92.0" +title = "Announcing Rust 1.92.0" +authors = ["The Rust Release Team"] +aliases = ["releases/1.92.0"] + +[extra] +release = true ++++ + +The Rust team is happy to announce a new version of Rust, 1.92.0. Rust is a programming language empowering everyone to build reliable and efficient software. + +If you have a previous version of Rust installed via `rustup`, you can get 1.92.0 with: + +```console +$ rustup update stable +``` + +If you don't have it already, you can [get `rustup`](https://www.rust-lang.org/install.html) from the appropriate page on our website, and check out the [detailed release notes for 1.92.0](https://doc.rust-lang.org/stable/releases.html#version-1920-2025-12-11). + +If you'd like to help us out by testing future releases, you might consider updating locally to use the beta channel (`rustup default beta`) or the nightly channel (`rustup default nightly`). Please [report](https://github.com/rust-lang/rust/issues/new/choose) any bugs you might come across! + +## What's in 1.92.0 stable + +### Deny-by-default never type lints + +The language and compiler teams continue to work on stabilization of the [never type](https://doc.rust-lang.org/stable/std/primitive.never.html). In this release the [`never_type_fallback_flowing_into_unsafe`](https://doc.rust-lang.org/beta/rustc/lints/listing/deny-by-default.html#dependency-on-unit-never-type-fallback) and [`dependency_on_unit_never_type_fallback`](https://doc.rust-lang.org/beta/rustc/lints/listing/deny-by-default.html#dependency-on-unit-never-type-fallback) future compatibility lints were made deny-by-default, meaning they will cause a compilation error when detected. + +These lints detect code which is likely to be broken by the never type stabilization. It is highly advised to fix them if they are reported in your crate. + +### `unused_must_use` no longer warns about `Result<(), UninhabitedType>` + +Rust's `unused_must_use` lint warns when ignoring the return value of a function, if the function or its return type is annotated with `#[must_use]`. For instance, this warns if ignoring a return type of `Result`, to remind you to use `?`, or something like `.expect("...")`. + +However, some functions return `Result`, but the error type they use is not actually "inhabited", meaning it can never exist in real code (e.g. the [`!`](https://doc.rust-lang.org/std/primitive.never.html) or [`Infallible`](https://doc.rust-lang.org/std/convert/enum.Infallible.html) types). + +The `unused_must_use` lint now no longer warns on `Result<(), UninhabitedType>`, or on `ControlFlow`. For instance, it will not warn on `Result<(), !>`. This avoids having to check for an error that can never happen. + +```rust +fn can_never_fail() -> Result<(), !> { + // ... + Ok(()) +} + +fn main() { + can_never_fail() +} +``` + +This is particularly useful with the common pattern of a trait with an associated error type, where the error type may *sometimes* be infallible: + +```rust +trait UsesAssocErrorType { + type Error; + fn method(&self) -> Result<(), Self::Error>; +} + +struct CannotFail; +impl UsesAssocErrorType for CannotFail { + type Error = !; + fn method(&self) -> Result<(), Self::Error> { + Ok(()) + } +} + +struct CanFail; +impl UsesAssocErrorType for CanFail { + type Error = std::io::Error; + fn method(&self) -> Result<(), Self::Error> { + Err(std::io::Error::other("something went wrong")) + } +} + +fn main() { + CannotFail.method(); // No error + CanFail.method(); // Error: unused `Result` that must be used +} +``` + +### Emit unwind tables even when `-Cpanic=abort` is enabled on linux + +Backtraces with `-Cpanic=abort` previously worked in Rust 1.22 but were broken in Rust 1.23, as we stopped emitting unwind tables with `-Cpanic=abort`. In Rust 1.45 a workaround in the form of `-Cforce-unwind-tables=yes` was stabilized. + +In Rust 1.92 unwind tables will be emitted by default even when `-Cpanic=abort` is specified, allowing for backtraces to work properly. If unwind tables are not desired then users should use `-Cforce-unwind-tables=no` to explicitly disable them being emitted. + +### Validate input to `#[macro_export]` + +Over the past few releases, many changes were made to the way built-in attributes are processed in the compiler. This should greatly improve the error messages and warnings rust gives for built-in attributes and especially make these diagnostics more consistent among all of the over 100 built-in attributes. + +To give a small example, in this release specifically, Rust became stricter in checking what arguments are allowed to `macro_export` by [upgrading that check to a "deny-by-default lint" that will be reported in dependencies.](https://github.com/rust-lang/rust/pull/143857). + +### Restrictions on user code impls of `DerefMut` for `Pin` + +A soundness issue with `Pin` has been solved by preventing third-party crates from implementing `DerefMut` for `Pin` when `T` is a local type that doesn't implement `DerefMut`. + +### Stabilized APIs + +... + +These previously stable APIs are now stable in const contexts: + +... + +### Platform Support + +Refer to Rust’s [platform support page][platform-support] for more information on Rust’s tiered platform support. + +### Other changes + +Check out everything that changed in [Rust](https://github.com/rust-lang/rust/releases/tag/1.92.0), [Cargo](https://doc.rust-lang.org/nightly/cargo/CHANGELOG.html#cargo-192-2025-12-11), and [Clippy](https://github.com/rust-lang/rust-clippy/blob/master/CHANGELOG.md#rust-192). + +## Contributors to 1.92.0 + +Many people came together to create Rust 1.92.0. We couldn't have done it without all of you. [Thanks!](https://thanks.rust-lang.org/rust/1.92.0/) + +[platform-support]: https://doc.rust-lang.org/rustc/platform-support.html