**NOTE:** Use the :pencil: links to edit those that have a `relnotes-tracking-issue`, and they will be updated when we regenerate the notes periodically (manually). ----- Version 1.98.0 (2026-08-20) ========================== <a id="1.98.0-Language"></a> Language -------- - [Allow shortening lifetime of `&mut` when unsize-coercing, even in an invariant position.](https://github.com/rust-lang/rust/pull/149219) For example, you can now coerce a `Cell<&'long mut i32>` to a `Cell<&'short mut dyn Send>`. Such shortenings were already previously allowed when coercing a `&mut` to a `&`, or coercing a `&` to a `&`. [:pencil:](https://github.com/rust-lang/rust/issues/156457) - [riscv: `d`, `e`, and `f` target_features are now stable in `cfg(target_feature = "?")`](https://github.com/rust-lang/rust/pull/156188) [:pencil:](https://github.com/rust-lang/rust/issues/157534) <a id="1.98.0-Compiler"></a> Compiler -------- <a id="1.98.0-Platform-Support"></a> Platform Support ---------------- - [Add `powerpc64-unknown-linux-gnuelfv2` as Tier 3](https://github.com/rust-lang/rust/pull/144220) [:pencil:](https://github.com/rust-lang/rust/issues/160462) - [Add `aarch64-unknown-linux-pauthtest` as Tier 3 target](https://github.com/rust-lang/rust/pull/155722) [:pencil:](https://github.com/rust-lang/rust/issues/160689) - [Promote `thumbv7a-none-eabi` Tier 2](https://github.com/rust-lang/rust/pull/155763) - [Promote `thumbv7a-none-eabihf` Tier 2](https://github.com/rust-lang/rust/pull/155763) - [Promote `thumbv7r-none-eabi` Tier 2](https://github.com/rust-lang/rust/pull/155763) - [Promote `thumbv7r-none-eabihf` Tier 2](https://github.com/rust-lang/rust/pull/155763) - [Promote `thumbv8r-none-eabihf` Tier 2](https://github.com/rust-lang/rust/pull/155763) [:pencil:](https://github.com/rust-lang/rust/issues/160688) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. [platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html <a id="1.98.0-Libraries"></a> Libraries --------- - [Change `Location<'_>` lifetime to `'static` in `Panic[Hook]Info`](https://github.com/rust-lang/rust/pull/146561) [:pencil:](https://github.com/rust-lang/rust/issues/148297) - [Document panic in `RangeInclusive::from(legacy::RangeInclusive)`](https://github.com/rust-lang/rust/pull/155421) [:pencil:](https://github.com/rust-lang/rust/issues/158142) - [Document that `ManuallyDrop`'s `Box` interaction has been fixed](https://github.com/rust-lang/rust/pull/155750) [:pencil:](https://github.com/rust-lang/rust/issues/156042) - [Stabilize `core::range::{legacy, RangeFull, RangeTo}`](https://github.com/rust-lang/rust/pull/156629/) <a id="1.98.0-Stabilized-APIs"></a> Stabilized APIs --------------- - [`core::fmt::NumBuffer`](https://doc.rust-lang.org/stable/core/fmt/struct.NumBuffer.html) - [`<{integer}>::format_into`](https://doc.rust-lang.org/stable/core/primitive.usize.html#method.format_into) [:pencil:](https://github.com/rust-lang/rust/issues/160690) - [`Send/Sync for std::process::CommandArgs`](https://doc.rust-lang.org/stable/std/process/struct.CommandArgs.html#impl-Send-for-CommandArgs%3C'a%3E) [:pencil:](https://github.com/rust-lang/rust/issues/156335) - [`{fN}::algebraic_add`](https://doc.rust-lang.org/stable/core/primitive.f32.html#method.algebraic_add) - [`{fN}::algebraic_sub`](https://doc.rust-lang.org/stable/core/primitive.f32.html#method.algebraic_sub) - [`{fN}::algebraic_mul`](https://doc.rust-lang.org/stable/core/primitive.f32.html#method.algebraic_mul) - [`{fN}::algebraic_div`](https://doc.rust-lang.org/stable/core/primitive.f32.html#method.algebraic_div) - [`{fN}::algebraic_rem`](https://doc.rust-lang.org/stable/core/primitive.f32.html#method.algebraic_rem) [:pencil:](https://github.com/rust-lang/rust/issues/157864) - [`NonZero<{integer}>::from_str_radix`](https://doc.rust-lang.org/stable/core/num/struct.NonZero.html#method.from_str_radix-4) [:pencil:](https://github.com/rust-lang/rust/issues/160698) - [`String::from_utf16le`](https://doc.rust-lang.org/stable/std/string/struct.String.html#method.from_utf16le) - [`String::from_utf16le_lossy`](https://doc.rust-lang.org/stable/std/string/struct.String.html#method.from_utf16le_lossy) - [`String::from_utf16be`](https://doc.rust-lang.org/beta/std/string/struct.String.html#method.from_utf16be) - [`String:;from_utf16be_lossy`](https://doc.rust-lang.org/stable/std/string/struct.String.html#method.from_utf16be_lossy) [:pencil:](https://github.com/rust-lang/rust/issues/160699) - [`[T]::strip_circumfix`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.strip_circumfix) - [`str::strip_circumfix`](https://doc.rust-lang.org/stable/core/primitive.str.html#method.strip_circumfix) [:pencil:](https://github.com/rust-lang/rust/issues/160694) - [`Atomic<T>::from_mut`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.Atomic.html#method.from_mut) - [`Atomic<T>::get_mut_slice`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.Atomic.html#method.get_mut_slice) - [`Atomic<T>::from_mut_slice`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.Atomic.html#method.from_mut_slice) [:pencil:](https://github.com/rust-lang/rust/issues/160686) These previously stable APIs are now stable in const contexts: <a id="1.98.0-Cargo"></a> Cargo ----- <a id="1.98.0-Rustdoc"></a> Rustdoc ----- <a id="1.98.0-Compatibility-Notes"></a> Compatibility Notes ------------------- - [If fully elided, lifetime bounds of trait object types may now resolve differently or even get rejected in very specific niche scenarios](https://github.com/rust-lang/rust/pull/129543) [:pencil:](https://github.com/rust-lang/rust/issues/156449) - [Error in more cases of ambiguous imports](https://github.com/rust-lang/rust/pull/145108) [:pencil:](https://github.com/rust-lang/rust/issues/156651) - [Switch the destructors implementation for thread locals on Windows to use FLS](https://github.com/rust-lang/rust/pull/148799) [:pencil:](https://github.com/rust-lang/rust/issues/156334) - [Convert some cases of the `ambiguous_glob_imports` lint into a hard error](https://github.com/rust-lang/rust/pull/149195) [:pencil:](https://github.com/rust-lang/rust/issues/156648) - [Where-bounds of the form `Type = Type` and `Type == Type` are no longer syntactically allowed](https://github.com/rust-lang/rust/pull/153513) [:pencil:](https://github.com/rust-lang/rust/issues/154816) - [Ensure Send/Sync is not implemented for std::env::Vars{,Os}](https://github.com/rust-lang/rust/pull/155153) [:pencil:](https://github.com/rust-lang/rust/issues/156521) - [Fix that in some attributes, arguments were not properly rejected](https://github.com/rust-lang/rust/pull/155193) [:pencil:](https://github.com/rust-lang/rust/issues/156641) - [`repr(transparent)` is now more strict about which fields have "trivial" layout and hence can be ignored: `repr(C)` types, types with private fields, and `#[non_exhaustive]` types are no longer considered "trivial"](https://github.com/rust-lang/rust/pull/155299) [:pencil:](https://github.com/rust-lang/rust/issues/157730) - [Correctly check whether types have equal size in `transmute()` when some `repr` attributes are involved.](https://github.com/rust-lang/rust/pull/155418) [:pencil:](https://github.com/rust-lang/rust/issues/156852) - [Add deny-by-default `invalid_runtime_symbol_definitions` lint and warn-by-default `suspicious_runtime_symbol_definitions` lint](https://github.com/rust-lang/rust/pull/155521) - The lints currently specifically targets `core` runtime symbols like `memcmp`, `memset`, `strlen`, ... and is planned be embellished in the next few releases. [:pencil:](https://github.com/rust-lang/rust/issues/156519) - [More characters are escaped when printing strings an chars](https://github.com/rust-lang/rust/pull/155527) [:pencil:](https://github.com/rust-lang/rust/issues/156782) - [Implement fast path for `derive(PartialOrd)` when deriving `Ord`](https://github.com/rust-lang/rust/pull/155598) This can break crates in practice where a type's PartialOrd and Ord impls were inconsistent with each other. [:pencil:](https://github.com/rust-lang/rust/issues/159555) - [Add temporary scope to `assert_eq` and `assert_ne`](https://github.com/rust-lang/rust/pull/155739) [:pencil:](https://github.com/rust-lang/rust/issues/158022) - [lint on `core::ffi::c_void` as a return type](https://github.com/rust-lang/rust/pull/156379) [:pencil:](https://github.com/rust-lang/rust/issues/156853) - Closed a hole in the pattern matching [structural equality](https://doc.rust-lang.org/reference/patterns.html#constant-patterns) check, preventing cases where a match of a constant would be allowed, despite disagreeing with a manually written `PartialEq` implementation, when a `derive(PartialEq)` implementation for that type also exists. [:pencil:](https://github.com/rust-lang/rust/issues/157865) - [On Emscripten the WASM exception handling ABI is now unconditionally used](https://github.com/rust-lang/rust/pull/156928) The `-Zemscripten-wasm-eh=false` flag to switch back to JS exceptions has been removed. [:pencil:](https://github.com/rust-lang/rust/issues/158091) - [The UNSAFE_CODE lint is now consistently emitted for all unsafe attributes](https://github.com/rust-lang/rust/pull/157201) [:pencil:](https://github.com/rust-lang/rust/issues/157704) - [Solaris: remove `File::lock` implementation, it has the wrong semantics (return "unsupported" instead)](https://github.com/rust-lang/rust/pull/157509) [:pencil:](https://github.com/rust-lang/rust/issues/157510) - [Windows-gnu targets now specify baseline tools versions](https://github.com/rust-lang/rust/pull/158020) [:pencil:](https://github.com/rust-lang/rust/issues/158296) <a id="1.98.0-Internal-Changes"></a> Internal Changes ---------------- These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. Other -----