rust-lang/rust

📦 Language

• [Allow passing `expr` metavariable to `cfg`](https://github.com/rust-lang/rust/pull/146961)
• [Always coerce never types in tuple expressions](https://github.com/rust-lang/rust/pull/147834)
• [Avoid incorrect inference guidance of function arguments in rare cases](https://github.com/rust-lang/rust/pull/150316)
• [Support s390x vector registers in inline assembly](https://github.com/rust-lang/rust/pull/154184)
• [Allow using constants of type `ManuallyDrop` as patterns (fixing a regression introduced in 1.94.0)](https://github.com/rust-lang/rust/pull/154891)
• <a id="1.96.0-Compiler"></a>

📦 Compiler

• [Enable link relaxation feature for LoongArch Linux targets](https://github.com/rust-lang/rust/pull/153427)
• [Update `riscv64gc-unknown-fuchsia` baseline to RVA22 + vector](https://github.com/rust-lang/rust/pull/155072)
• <a id="1.96.0-Libraries"></a>

📦 Libraries

• [Support iterating over ranges of `NonZero` integers](https://github.com/rust-lang/rust/pull/127534)
• [refactor 'valid for read/write' definition: exclude null; add that as an exception on individual methods instead](https://github.com/rust-lang/rust/pull/152615)
• [Fix SGX delayed host lookup via ToSocketAddr](https://github.com/rust-lang/rust/pull/152851)
• <a id="1.96.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`assert_matches!`](https://doc.rust-lang.org/stable/std/macro.assert_matches.html)
• [`debug_assert_matches!`](https://doc.rust-lang.org/stable/std/macro.debug_assert_matches.html)
• [`From<T> for AssertUnwindSafe<T>`](https://doc.rust-lang.org/stable/std/panic/struct.AssertUnwindSafe.html#impl-From%3CT%3E-for-AssertUnwindSafe%3CT%3E)
• [`From<T> for LazyCell<T, F>`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#impl-From%3CT%3E-for-LazyCell%3CT,+F%3E)
• [`From<T> for LazyLock<T, F>`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#impl-From%3CT%3E-for-LazyLock%3CT,+F%3E)
• [`core::range::RangeToInclusive`](https://doc.rust-lang.org/stable/core/range/struct.RangeToInclusive.html)
• [`core::range::RangeToInclusiveIter`](https://doc.rust-lang.org/stable/core/range/struct.RangeToInclusiveIter.html)
• [`core::range::RangeFrom`](https://doc.rust-lang.org/stable/core/ops/struct.RangeFrom.html)
• + 4 more

📦 Cargo

• [Allow a dependency to specify both a git repository and an alternate registry.](https://github.com/rust-lang/cargo/pull/16810/) Just like with crates.io, the git repository will be used locally, but the registry version will be used when published.
• [Added `target.'cfg(..)'.rustdocflags` support in configuration.](https://github.com/rust-lang/cargo/pull/16846)
• Fixed [CVE-2026-5222](https://blog.rust-lang.org/2026/05/25/cve-2026-5222/) and [CVE-2026-5223](https://blog.rust-lang.org/2026/05/25/cve-2026-5223/).
• <a id="1.96-Rustdoc"></a>

📝 Rustdoc

• [Deprecation notes are now rendered like any other documentation](https://github.com/rust-lang/rust/pull/149931). Previously they used the css `white-space: pre-wrap;` property and stripped any `<p>` elements from the rendered html, however this caused issues and unintuitive behavior. The new behavior should be more predictable, however some multi-line deprecation notes will now be rendered as as single lines. If this is undesirable, you can use the standard markdown method of forcing a linebreak, which is two spaces followed by a newline (`"\n"`).
• [Don't emit rustdoc `missing_doc_code_examples` lint on impl items](https://github.com/rust-lang/rust/pull/154048)
• [Separate methods and associated functions in sidebar](https://github.com/rust-lang/rust/pull/154644)
• <a id="1.96.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Fix layout of `#[repr(Int)]` enums in some edge cases involving fields of uninhabited zero-sized types](https://github.com/rust-lang/rust/pull/146989)
• [Prevent unsize-coercing into `Pin<Foo>` where `Foo` doesn't implement `Deref`. Some such coercions were previously allowed, but produce a type with no useful public API.](https://github.com/rust-lang/rust/pull/149218)
• [rustc: Stop passing `--allow-undefined` on wasm targets](https://github.com/rust-lang/rust/pull/149868)
• [Gate the accidentally stabilized `#![reexport_test_harness_main]` attribute](https://github.com/rust-lang/rust/pull/152210)
• [Error on return-position-impl-trait-in-traits whose types are too private](https://github.com/rust-lang/rust/pull/152543)
• [Report the `uninhabited_static` lint in dependencies and make it deny-by-default](https://github.com/rust-lang/rust/pull/152853)
• [Distributed builds now contain non-split debuginfo for windows-gnu](https://github.com/rust-lang/rust/pull/152870) This appears to improve the quality of backtraces. This change has no effect on the defaults for the output of rustc/cargo on these targets.
• [Check const generic arguments are correctly typed in more positions](https://github.com/rust-lang/rust/pull/152931)
• + 6 more

📋 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.
• [JSON targets: `aarch64` softfloat targets now have to have `rustc_abi` set to `"softfloat"`](https://github.com/rust-lang/rust/pull/152941)
• [target specs: stricter checks for LLVM ABI values, and correlate that with `cfg(target_abi)`](https://github.com/rust-lang/rust/pull/153769)

📦 Language

• [Stabilize `if let` guards on match arms](https://github.com/rust-lang/rust/pull/141295)
• [`irrefutable_let_patterns` lint no longer lints on let chains](https://github.com/rust-lang/rust/pull/146832)
• [Support importing path-segment keywords with renaming](https://github.com/rust-lang/rust/pull/146972)
• [Stabilize inline assembly for PowerPC and PowerPC64](https://github.com/rust-lang/rust/pull/147996)
• [const-eval: be more consistent in the behavior of padding during typed copies](https://github.com/rust-lang/rust/pull/148967)
• [Const blocks are no longer evaluated to determine if expressions involving fallible operations can implicitly be constant-promoted.](https://github.com/rust-lang/rust/pull/150557). Expressions whose ability to implicitly be promoted would depend on the result of a const block are no longer implicitly promoted.
• [Make operational semantics of pattern matching independent of crate and module](https://github.com/rust-lang/rust/pull/150681)
• <a id="1.95-Compiler"></a>

📦 Compiler

• [Stabilize `--remap-path-scope` for controlling the scoping of how paths get remapped in the resulting binary](https://github.com/rust-lang/rust/pull/147611)
• [Apply patches for CVE-2026-6042 and CVE-2026-40200 to vendored musl](https://github.com/rust-lang/rust/pull/155171)
• <a id="1.95-Platform-Support"></a>

📦 Platform Support

• [Promote `powerpc64-unknown-linux-musl` to Tier 2 with host tools](https://github.com/rust-lang/rust/pull/149962)
• [Promote `aarch64-apple-tvos` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• [Promote `aarch64-apple-tvos-sim` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• [Promote `aarch64-apple-watchos` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• [Promote `aarch64-apple-watchos-sim` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• [Promote `aarch64-apple-visionos` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• [Promote `aarch64-apple-visionos-sim` to Tier 2](https://github.com/rust-lang/rust/pull/152021)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• + 1 more

📦 Libraries

• [`thread::scope`: document how join interacts with TLS destructors](https://github.com/rust-lang/rust/pull/149482)
• [Speed up `str::contains` on aarch64 targets with `neon` target feature enabled by default](https://github.com/rust-lang/rust/pull/152176)
• <a id="1.95-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`MaybeUninit<[T; N]>: From<[MaybeUninit<T>; N]>`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#impl-From%3CMaybeUninit%3C%5BT;+N%5D%3E%3E-for-%5BMaybeUninit%3CT%3E;+N%5D)
• [`MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>; N]>`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#impl-AsRef%3C%5BMaybeUninit%3CT%3E;+N%5D%3E-for-MaybeUninit%3C%5BT;+N%5D%3E)
• [`MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>]>`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#impl-AsRef%3C%5BMaybeUninit%3CT%3E%5D%3E-for-MaybeUninit%3C%5BT;+N%5D%3E)
• [`MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>; N]>`](https://doc.rust-lang.org/beta/std/mem/union.MaybeUninit.html#impl-AsMut%3C%5BMaybeUninit%3CT%3E;+N%5D%3E-for-MaybeUninit%3C%5BT;+N%5D%3E)
• [`MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>]>`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#impl-AsMut%3C%5BMaybeUninit%3CT%3E%5D%3E-for-MaybeUninit%3C%5BT;+N%5D%3E)
• [`[MaybeUninit<T>; N]: From<MaybeUninit<[T; N]>>`](https://doc.rust-lang.org/stable/std/mem/union.MaybeUninit.html#impl-From%3C%5BMaybeUninit%3CT%3E;+N%5D%3E-for-MaybeUninit%3C%5BT;+N%5D%3E)
• [`Cell<[T; N]>: AsRef<[Cell<T>; N]>`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#impl-AsRef%3C%5BCell%3CT%3E;+N%5D%3E-for-Cell%3C%5BT;+N%5D%3E)
• [`Cell<[T; N]>: AsRef<[Cell<T>]>`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#impl-AsRef%3C%5BCell%3CT%3E%5D%3E-for-Cell%3C%5BT;+N%5D%3E)
• + 34 more

📝 Rustdoc

• [In search results, rank unstable items lower](https://github.com/rust-lang/rust/pull/149460)
• [Add new "hide deprecated items" setting in rustdoc](https://github.com/rust-lang/rust/pull/151091)
• <a id="1.95-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Array coercions may now result in less inference constraints than before](https://github.com/rust-lang/rust/pull/140283)
• Importing `$crate` without renaming, i.e. `use $crate::{self};`, is now no longer permitted due to stricter error checking for `self` imports.
• [const-eval: be more consistent in the behavior of padding during typed copies.](https://github.com/rust-lang/rust/pull/148967) In very rare cases, this may cause compilation errors due to bytes from parts of a pointer ending up in the padding bytes of a `const` or `static`.
• [A future-incompatibility warning lint `ambiguous_glob_imported_traits` is now reported when using an ambiguously glob imported trait](https://github.com/rust-lang/rust/pull/149058)
• [Check lifetime bounds of types mentioning only type parameters](https://github.com/rust-lang/rust/pull/149389)
• [Report more visibility-related ambiguous import errors](https://github.com/rust-lang/rust/pull/149596)
• [Deprecate `Eq::assert_receiver_is_total_eq` and emit future compatibility warnings on manual impls](https://github.com/rust-lang/rust/pull/149978)
• [powerpc64: Use the ELF ABI version set in target spec instead of guessing](https://github.com/rust-lang/rust/pull/150468) (fixes the ELF ABI used by the OpenBSD target)
• + 6 more

📋 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.
• [Update to LLVM 22](https://github.com/rust-lang/rust/pull/150722)

📋 Changes

• [Fix `std::thread::spawn` on wasm32-wasip1-threads](https://github.com/rust-lang/rust/pull/153634)
• [Remove new methods added to `std::os::windows::fs::OpenOptionsExt`](https://github.com/rust-lang/rust/pull/153491) The new methods were unstable, but the trait itself is not sealed and so cannot be extended with non-default methods.
• [Clippy: fix ICE in `match_same_arms`](https://github.com/rust-lang/rust-clippy/pull/16685)
• [Cargo: update tar to 0.4.45](https://github.com/rust-lang/cargo/pull/16769) This resolves CVE-2026-33055 and CVE-2026-33056. Users of crates.io are not affected. See [blog](https://blog.rust-lang.org/2026/03/21/cve-2026-33056/) for more details.

📦 Language

• [Impls and impl items inherit `dead_code` lint level of the corresponding traits and trait items](https://github.com/rust-lang/rust/pull/144113)
• [Stabilize additional 29 RISC-V target features including large portions of the RVA22U64 / RVA23U64 profiles](https://github.com/rust-lang/rust/pull/145948)
• [Add warn-by-default `unused_visibilities` lint for visibility on `const _` declarations](https://github.com/rust-lang/rust/pull/147136)
• [Update to Unicode 17](https://github.com/rust-lang/rust/pull/148321)
• [Avoid incorrect lifetime errors for closures](https://github.com/rust-lang/rust/pull/148329)
• <a id="1.94.0-Platform-Support"></a>

📦 Platform Support

• [Add `riscv64im-unknown-none-elf` as a tier 3 target](https://github.com/rust-lang/rust/pull/148790)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.94.0-Libraries"></a>

📦 Libraries

• [Relax `T: Ord` bound for some `BinaryHeap<T>` methods.](https://github.com/rust-lang/rust/pull/149408)
• <a id="1.94.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`<[T]>::array_windows`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.array_windows)
• [`<[T]>::element_offset`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.element_offset)
• [`LazyCell::get`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get)
• [`LazyCell::get_mut`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.get_mut)
• [`LazyCell::force_mut`](https://doc.rust-lang.org/stable/std/cell/struct.LazyCell.html#method.force_mut)
• [`LazyLock::get`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get)
• [`LazyLock::get_mut`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.get_mut)
• [`LazyLock::force_mut`](https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html#method.force_mut)
• + 13 more

📦 Cargo

• Stabilize the config include key. The top-level include config key allows loading additional config files, enabling better organization, sharing, and management of Cargo configurations across projects and environments. [docs](https://doc.rust-lang.org/nightly/cargo/reference/config.html#including-extra-configuration-files) [\#16284](https://github.com/rust-lang/cargo/pull/16284)
• Stabilize the pubtime field in registry index. This records when a crate version was published and enables time-based dependency resolution in the future. Note that crates.io will gradually backfill existing packages when a new version is published. Not all crates have pubtime yet. [\#16369](https://github.com/rust-lang/cargo/pull/16369) [\#16372](https://github.com/rust-lang/cargo/pull/16372)
• Cargo now parses [TOML v1.1](https://toml.io/en/v1.1.0) for manifests and configuration files. Note that using these features in Cargo.toml will raise your development MSRV, but the published manifest remains compatible with older parsers. [\#16415](https://github.com/rust-lang/cargo/pull/16415)
• [Make `CARGO_BIN_EXE_<crate>` available at runtime ](https://github.com/rust-lang/cargo/pull/16421/)
• <a id="1.94.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Forbid freely casting lifetime bounds of `dyn`-types](https://github.com/rust-lang/rust/pull/136776)
• [Make closure capturing have consistent and correct behaviour around patterns](https://github.com/rust-lang/rust/pull/138961) Some finer details of how precise closure captures get affected by pattern matching have been changed. In some cases, this can cause a non-move closure that was previously capturing an entire variable by move, to now capture only part of that variable by move, and other parts by borrow. This can cause the borrow checker to complain where it previously didn't, or cause `Drop` to run at a different point in time.
• [Standard library macros are now imported via prelude, not via injected `#[macro_use]`](https://github.com/rust-lang/rust/pull/139493) This will raise an error if macros of the same name are glob imported. For example if a crate defines their own `matches` macro and then glob imports that, it's now ambiguous whether the custom or standard library `matches` is meant and an explicit import of the name is required to resolve the ambiguity. One exception is `core::panic` and `std::panic`, if their import is ambiguous a new warning ([`ambiguous_panic_imports`](https://github.com/rust-lang/rust/issues/147319)) is raised. This may raise a new warning ([`ambiguous_panic_imports`](https://github.com/rust-lang/rust/issues/147319)) on `#![no_std]` code glob importing the std crate. Both `core::panic!` and `std::panic!` are then in scope and which is used is ambiguous.
• [Don't strip shebang in expression-context `include!(…)`s](https://github.com/rust-lang/rust/pull/146377) This can cause previously working includes to no longer compile if they included files which started with a shebang.
• [Ambiguous glob reexports are now also visible cross-crate](https://github.com/rust-lang/rust/pull/147984) This unifies behavior between local and cross-crate errors on these exports, which may introduce new ambiguity errors.
• [Don't normalize where-clauses before checking well-formedness](https://github.com/rust-lang/rust/pull/148477)
• [Introduce a future compatibility warning on codegen attributes on body-free trait methods](https://github.com/rust-lang/rust/pull/148756) These attributes currently have no effect in this position.
• [On Windows `std::time::SystemTime::checked_sub_duration` will return `None` for times before the Windows epoch (1/1/1601)](https://github.com/rust-lang/rust/pull/148825)
• + 3 more

📋 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.
• [Switch to `annotate-snippets` for error emission](https://github.com/rust-lang/rust/pull/150032) This should preserve mostly the same outputs in rustc error messages.

📋 Changes

• [Don't try to recover keyword as non-keyword identifier](https://github.com/rust-lang/rust/pull/150590), fixing an ICE that especially [affected rustfmt](https://github.com/rust-lang/rustfmt/issues/6739).
• [Fix `clippy::panicking_unwrap` false-positive on field access with implicit deref](https://github.com/rust-lang/rust-clippy/pull/16196).
• [Revert "Update wasm-related dependencies in CI"](https://github.com/rust-lang/rust/pull/152259), fixing file descriptor leaks on the `wasm32-wasip2` target.

📦 Language

• [Stabilize several s390x `vector`-related target features and the `is_s390x_feature_detected!` macro](https://github.com/rust-lang/rust/pull/145656)
• [Stabilize declaration of C-style variadic functions for the `system` ABI](https://github.com/rust-lang/rust/pull/145954)
• [Emit error when using some keyword as a `cfg` predicate](https://github.com/rust-lang/rust/pull/146978)
• [Stabilize `asm_cfg`](https://github.com/rust-lang/rust/pull/147736)
• [During const-evaluation, support copying pointers byte-by-byte](https://github.com/rust-lang/rust/pull/148259)
• [LUB coercions now correctly handle function item types, and functions with differing safeties](https://github.com/rust-lang/rust/pull/148602)
• [Allow `const` items that contain mutable references to `static` (which is *very* unsafe, but not *always* UB)](https://github.com/rust-lang/rust/pull/148746)
• [Add warn-by-default `const_item_interior_mutations` lint to warn against calls which mutate interior mutable `const` items](https://github.com/rust-lang/rust/pull/148407)
• + 2 more

📦 Compiler

• [Stabilize `-Cjump-tables=bool`](https://github.com/rust-lang/rust/pull/145974). The flag was previously called `-Zno-jump-tables`.
• <a id="1.93.0-Platform-Support"></a>

📦 Platform Support

• [Promote `riscv64a23-unknown-linux-gnu` to Tier 2 (without host tools)](https://github.com/rust-lang/rust/pull/148435)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.93.0-Libraries"></a>

📦 Libraries

• [Stop internally using `specialization` on the `Copy` trait as it is unsound in the presence of lifetime dependent `Copy` implementations. This may result in some performance regressions as some standard library APIs may now call `Clone::clone` instead of performing bitwise copies](https://github.com/rust-lang/rust/pull/135634)
• [Allow the global allocator to use thread-local storage and `std::thread::current()`](https://github.com/rust-lang/rust/pull/144465)
• [Make `BTree::append` not update existing keys when appending an entry which already exists](https://github.com/rust-lang/rust/pull/145628)
• [Don't require `T: RefUnwindSafe` for `vec::IntoIter<T>: UnwindSafe`](https://github.com/rust-lang/rust/pull/145665)
• <a id="1.93.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`<[MaybeUninit<T>]>::assume_init_drop`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.assume_init_drop)
• [`<[MaybeUninit<T>]>::assume_init_ref`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.assume_init_ref)
• [`<[MaybeUninit<T>]>::assume_init_mut`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.assume_init_mut)
• [`<[MaybeUninit<T>]>::write_copy_of_slice`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.write_copy_of_slice)
• [`<[MaybeUninit<T>]>::write_clone_of_slice`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.write_clone_of_slice)
• [`String::into_raw_parts`](https://doc.rust-lang.org/stable/std/string/struct.String.html#method.into_raw_parts)
• [`Vec::into_raw_parts`](https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.into_raw_parts)
• [`<iN>::unchecked_neg`](https://doc.rust-lang.org/stable/std/primitive.isize.html#method.unchecked_neg)
• + 16 more

📦 Cargo

• [Enable CARGO\_CFG\_DEBUG\_ASSERTIONS in build scripts based on profile](https://github.com/rust-lang/cargo/pull/16160/)
• [In `cargo tree`, support long forms for `--format` variables](https://github.com/rust-lang/cargo/pull/16204/)
• [Add `--workspace` to `cargo clean`](https://github.com/rust-lang/cargo/pull/16263/)
• <a id="1.93.0-Rustdoc"></a>

📝 Rustdoc

• [Remove `#![doc(document_private_items)]`](https://github.com/rust-lang/rust/pull/146495)
• [Include attribute and derive macros in search filters for "macros"](https://github.com/rust-lang/rust/pull/148176)
• [Include extern crates in search filters for `import`](https://github.com/rust-lang/rust/pull/148301)
• [Validate usage of crate-level doc attributes](https://github.com/rust-lang/rust/pull/149197). This means if any of `html_favicon_url`, `html_logo_url`, `html_playground_url`, `issue_tracker_base_url`, or `html_no_source` either has a missing value, an unexpected value, or a value of the wrong type, rustdoc will emit the deny-by-default lint `rustdoc::invalid_doc_attributes`.
• <a id="1.93.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Introduce `pin_v2` into the builtin attributes namespace](https://github.com/rust-lang/rust/pull/139751)
• [Update bundled musl to 1.2.5](https://github.com/rust-lang/rust/pull/142682)
• [On Emscripten, the unwinding ABI used when compiling with `panic=unwind` was changed from the JS exception handling ABI to the wasm exception handling ABI.](https://github.com/rust-lang/rust/pull/147224) If linking C/C++ object files with Rust objects, `-fwasm-exceptions` must be passed to the linker now. On nightly Rust, it is possible to get the old behavior with `-Zwasm-emscripten-eh=false -Zbuild-std`, but it will be removed in a future release.
• The `#[test]` attribute, used to define tests, was previously ignored in various places where it had no meaning (e.g on trait methods or types). Putting the `#[test]` attribute in these places is no longer ignored, and will now result in an error; this may also result in errors when generating rustdoc. [Error when `test` attribute is applied to structs](https://github.com/rust-lang/rust/pull/147841)
• Cargo now sets the `CARGO_CFG_DEBUG_ASSERTIONS` environment variable in more situations. This will cause crates depending on `static-init` versions 1.0.1 to 1.0.3 to fail compilation with "failed to resolve: use of unresolved module or unlinked crate `parking_lot`". See [the linked issue](https://github.com/rust-lang/rust/issues/150646#issuecomment-3718964342) for details.
• [User written types in the `offset_of!` macro are now checked to be well formed.](https://github.com/rust-lang/rust/issues/150465/)
• `cargo publish` no longer emits `.crate` files as a final artifact for user access when the `build.build-dir` config is unset
• [Upgrade the `deref_nullptr` lint from warn-by-default to deny-by-default](https://github.com/rust-lang/rust/pull/148122)
• + 3 more

📦 Language

• [Document `MaybeUninit` representation and validity](https://github.com/rust-lang/rust/pull/140463)
• [Allow `&raw [mut | const]` for union field in safe code](https://github.com/rust-lang/rust/pull/141469)
• [Prefer item bounds of associated types over where-bounds for auto-traits and `Sized`](https://github.com/rust-lang/rust/pull/144064)
• [Do not materialize `X` in `[X; 0]` when `X` is unsizing a const](https://github.com/rust-lang/rust/pull/145277)
• [Support combining `#[track_caller]` and `#[no_mangle]` (requires every declaration specifying `#[track_caller]` as well)](https://github.com/rust-lang/rust/pull/145724)
• [Make never type lints `never_type_fallback_flowing_into_unsafe` and `dependency_on_unit_never_type_fallback` deny-by-default](https://github.com/rust-lang/rust/pull/146167)
• [Allow specifying multiple bounds for same associated item, except in trait objects](https://github.com/rust-lang/rust/pull/146593)
• [Slightly strengthen higher-ranked region handling in coherence](https://github.com/rust-lang/rust/pull/146725)
• + 2 more

📦 Compiler

• [Make `mips64el-unknown-linux-muslabi64` link dynamically](https://github.com/rust-lang/rust/pull/146858)
• [Remove current code for embedding command-line args in PDB](https://github.com/rust-lang/rust/pull/147022) Command-line information is typically not needed by debugging tools, and the removed code was causing problems for incremental builds even on targets that don't use PDB debuginfo.
• <a id="1.92.0-Libraries"></a>

📦 Libraries

• [Specialize `Iterator::eq{_by}` for `TrustedLen` iterators](https://github.com/rust-lang/rust/pull/137122)
• [Simplify `Extend` for tuples](https://github.com/rust-lang/rust/pull/138799)
• [Added details to `Debug` for `EncodeWide`](https://github.com/rust-lang/rust/pull/140153).
• [`iter::Repeat::last`](https://github.com/rust-lang/rust/pull/147258) and [`count`](https://github.com/rust-lang/rust/pull/146410) will now panic, rather than looping infinitely.
• <a id="1.92.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`NonZero<u{N}>::div_ceil`](https://doc.rust-lang.org/stable/std/num/struct.NonZero.html#method.div_ceil)
• [`Location::file_as_c_str`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.file_as_c_str)
• [`RwLockWriteGuard::downgrade`](https://doc.rust-lang.org/stable/std/sync/struct.RwLockWriteGuard.html#method.downgrade)
• [`Box::new_zeroed`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed)
• [`Box::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed_slice)
• [`Rc::new_zeroed`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed)
• [`Rc::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed_slice)
• [`Arc::new_zeroed`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.new_zeroed)
• + 11 more

📦 Cargo

• [Added a new chapter](https://github.com/rust-lang/cargo/issues/16119) to the Cargo book, ["Optimizing Build Performance"](https://doc.rust-lang.org/stable/cargo/guide/build-performance.html).
• <a id="1.92.0-Rustdoc"></a>

📝 Rustdoc

• [If a trait item appears in rustdoc search, hide the corresponding impl items](https://github.com/rust-lang/rust/pull/145898). Previously a search for "last" would show both `Iterator::last` as well as impl methods like `std::vec::IntoIter::last`. Now these impl methods will be hidden, freeing up space for inherent methods like `BTreeSet::last`.
• [Relax rules for identifiers in search](https://github.com/rust-lang/rust/pull/147860). Previously you could only search for identifiers that were valid in rust code, now searches only need to be valid as part of an identifier. For example, you can now perform a search that starts with a digit.
• <a id="1.92.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Fix backtraces with `-C panic=abort` on Linux by generating unwind tables by default](https://github.com/rust-lang/rust/pull/143613). Build with `-C force-unwind-tables=no` to keep omitting unwind tables.
• <!-- end list -->
• As part of the larger effort refactoring compiler built-in attributes and their diagnostics, [the future-compatibility lint `invalid_macro_export_arguments` is upgraded to deny-by-default and will be reported in dependencies too.](https://github.com/rust-lang/rust/pull/143857)
• [Update the minimum external LLVM to 20](https://github.com/rust-lang/rust/pull/145071)
• [Prevent downstream `impl DerefMut for Pin<LocalType>`](https://github.com/rust-lang/rust/pull/145608)
• [Don't apply temporary lifetime extension rules to the arguments of non-extended `pin!` and formatting macros](https://github.com/rust-lang/rust/pull/145838)

📋 Changes

• [Enable file locking support in illumos](https://github.com/rust-lang/rust/pull/148322). This fixes Cargo not locking the build directory on illumos.
• [Fix `wasm_import_module` attribute cross-crate](https://github.com/rust-lang/rust/pull/148363). This fixes linker errors on WASM targets.

📦 Language

• [Lower pattern bindings in the order they're written and base drop order on primary bindings' order](https://github.com/rust-lang/rust/pull/143764)
• [Stabilize declaration of C-style variadic functions for `sysv64`, `win64`, `efiapi`, and `aapcs` ABIs](https://github.com/rust-lang/rust/pull/144066). This brings these ABIs in line with the C ABI: variadic functions can be declared in extern blocks but not defined.
• [Add `dangling_pointers_from_locals` lint to warn against dangling pointers from local variables](https://github.com/rust-lang/rust/pull/144322)
• [Upgrade `semicolon_in_expressions_from_macros` from warn to deny](https://github.com/rust-lang/rust/pull/144369)
• [Stabilize LoongArch32 inline assembly](https://github.com/rust-lang/rust/pull/144402)
• [Add warn-by-default `integer_to_ptr_transmutes` lint against integer-to-pointer transmutes](https://github.com/rust-lang/rust/pull/144531)
• [Stabilize `sse4a` and `tbm` target features](https://github.com/rust-lang/rust/pull/144542)
• [Add `target_env = "macabi"` and `target_env = "sim"` cfgs](https://github.com/rust-lang/rust/pull/139451) as replacements for the `target_abi` cfgs with the same values.
• + 1 more

📦 Compiler

• [Don't warn on never-to-any `as` casts as unreachable](https://github.com/rust-lang/rust/pull/144804)
• <a id="1.91.0-Platform-Support"></a>

📦 Platform Support

• [Promote `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm` to Tier 2 with host tools.](https://github.com/rust-lang/rust/pull/143031) Note: llvm-tools and MSI installers are missing but will be added in future releases.
• [Promote `aarch64-pc-windows-msvc` to Tier 1](https://github.com/rust-lang/rust/pull/145682)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.91.0-Libraries"></a>

📦 Libraries

• [Print thread ID in panic message](https://github.com/rust-lang/rust/pull/115746)
• [Fix overly restrictive lifetime in `core::panic::Location::file` return type](https://github.com/rust-lang/rust/pull/132087)
• [Guarantee parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`](https://github.com/rust-lang/rust/pull/139357)
• [Document assumptions about `Clone` and `Eq` traits](https://github.com/rust-lang/rust/pull/144330/)
• [`std::thread`: Return error if setting thread stack size fails](https://github.com/rust-lang/rust/pull/144210) This used to panic within the standard library.
• <a id="1.91.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`Path::file_prefix`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#method.file_prefix)
• [`AtomicPtr::fetch_ptr_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_add)
• [`AtomicPtr::fetch_ptr_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_sub)
• [`AtomicPtr::fetch_byte_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_add)
• [`AtomicPtr::fetch_byte_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_sub)
• [`AtomicPtr::fetch_or`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_or)
• [`AtomicPtr::fetch_and`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_and)
• [`AtomicPtr::fetch_xor`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_xor)
• + 61 more

📦 Cargo

• 🎉 Stabilize `build.build-dir`. This config sets the directory where intermediate build artifacts are stored. These artifacts are produced by Cargo and rustc during the build process. End users usually won't need to interact with them, and the layout inside `build-dir` is an implementation detail that may change without notice. ([config doc](https://doc.rust-lang.org/stable/cargo/reference/config.html#buildbuild-dir)) ([build cache doc](https://doc.rust-lang.org/stable/cargo/reference/build-cache.html)) [\#15833](https://github.com/rust-lang/cargo/pull/15833) [\#15840](https://github.com/rust-lang/cargo/pull/15840)
• The `--target` flag and the `build.target` configuration can now take literal `"host-tuple"` string, which will internally be substituted by the host machine's target triple. [\#15838](https://github.com/rust-lang/cargo/pull/15838) [\#16003](https://github.com/rust-lang/cargo/pull/16003) [\#16032](https://github.com/rust-lang/cargo/pull/16032)
• <a id="1.91.0-Rustdoc"></a>

📝 Rustdoc

• [In search results, rank doc aliases lower than non-alias items with the same name](https://github.com/rust-lang/rust/pull/145100)
• [Raw pointers now work in type-based search like references](https://github.com/rust-lang/rust/pull/145731). This means you can now search for things like `*const u8 ->`, and additionally functions that take or return raw pointers will now display their signature properly in search results.
• <a id="1.91.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Always require coroutine captures to be drop-live](https://github.com/rust-lang/rust/pull/144156)
• [Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var](https://github.com/rust-lang/rust/pull/131477). This should fix linking issues with `rustc` running inside Xcode. Libraries in `/usr/local/lib` may no longer be linked automatically, if you develop or use a crate that relies on this, you should explicitly set `cargo::rustc-link-search=/usr/local/lib` in a `build.rs` script.
• [Relaxed bounds in associated type bound position like in `TraitRef<AssocTy: ?Sized>` are now correctly forbidden](https://github.com/rust-lang/rust/pull/135331)
• [Add unstable `#[sanitize(xyz = "on|off")]` built-in attribute that shadows procedural macros with the same name](https://github.com/rust-lang/rust/pull/142681)
• [Fix the drop checker being more permissive for bindings declared with let-else](https://github.com/rust-lang/rust/pull/143028)
• [Be more strict when parsing attributes, erroring on many invalid attributes](https://github.com/rust-lang/rust/pull/144689)
• [Error on invalid `#[should_panic]` attributes](https://github.com/rust-lang/rust/pull/143808)
• [Error on invalid `#[link]` attributes](https://github.com/rust-lang/rust/pull/143193)
• + 14 more

📋 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.
• [Update to LLVM 21](https://github.com/rust-lang/rust/pull/143684)

📦 Language

• [Split up the `unknown_or_malformed_diagnostic_attributes` lint](https://github.com/rust-lang/rust/pull/140717). This lint has been split up into four finer-grained lints, with `unknown_or_malformed_diagnostic_attributes` now being the lint group that contains these lints:
• 1. `unknown_diagnostic_attributes`: unknown to the current compiler
• 2. `misplaced_diagnostic_attributes`: placed on the wrong item
• 3. `malformed_diagnostic_attributes`: malformed attribute syntax or options
• 4. `malformed_diagnostic_format_literals`: malformed format string literal
• [Allow constants whose final value has references to mutable/external memory, but reject such constants as patterns](https://github.com/rust-lang/rust/pull/140942)
• [Allow volatile access to non-Rust memory, including address 0](https://github.com/rust-lang/rust/pull/141260)
• <a id="1.90-Compiler"></a>

📦 Compiler

• [Use `lld` by default on `x86_64-unknown-linux-gnu`](https://github.com/rust-lang/rust/pull/140525).
• [Tier 3 `musl` targets now link dynamically by default](https://github.com/rust-lang/rust/pull/144410). Affected targets:
• `mips64-unknown-linux-muslabi64`
• `powerpc64-unknown-linux-musl`
• `powerpc-unknown-linux-musl`
• `powerpc-unknown-linux-muslspe`
• `riscv32gc-unknown-linux-musl`
• `s390x-unknown-linux-musl`
• + 2 more

📦 Platform Support

• [Demote `x86_64-apple-darwin` to Tier 2 with host tools](https://github.com/rust-lang/rust/pull/145252)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.90-Libraries"></a>

📦 Libraries

• [Stabilize `u*::{checked,overflowing,saturating,wrapping}_sub_signed`](https://github.com/rust-lang/rust/issues/126043)
• [Allow comparisons between `CStr`, `CString`, and `Cow<CStr>`](https://github.com/rust-lang/rust/pull/137268)
• [Remove some unsized tuple impls since unsized tuples can't be constructed](https://github.com/rust-lang/rust/pull/138340)
• [Set `MSG_NOSIGNAL` for `UnixStream`](https://github.com/rust-lang/rust/pull/140005)
• [`proc_macro::Ident::new` now supports `$crate`.](https://github.com/rust-lang/rust/pull/141996)
• [Guarantee the pointer returned from `Thread::into_raw` has at least 8 bytes of alignment](https://github.com/rust-lang/rust/pull/143859)
• <a id="1.90-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`u{n}::checked_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.usize.html#method.checked_sub_signed)
• [`u{n}::overflowing_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.usize.html#method.overflowing_sub_signed)
• [`u{n}::saturating_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.usize.html#method.saturating_sub_signed)
• [`u{n}::wrapping_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.usize.html#method.wrapping_sub_signed)
• [`impl Copy for IntErrorKind`](https://doc.rust-lang.org/stable/std/num/enum.IntErrorKind.html#impl-Copy-for-IntErrorKind)
• [`impl Hash for IntErrorKind`](https://doc.rust-lang.org/stable/std/num/enum.IntErrorKind.html#impl-Hash-for-IntErrorKind)
• [`impl PartialEq<&CStr> for CStr`](https://doc.rust-lang.org/stable/std/ffi/struct.CStr.html#impl-PartialEq%3C%26CStr%3E-for-CStr)
• [`impl PartialEq<CString> for CStr`](https://doc.rust-lang.org/stable/std/ffi/struct.CStr.html#impl-PartialEq%3CCString%3E-for-CStr)
• + 22 more

📦 Cargo

• [Add `http.proxy-cainfo` config for proxy certs](https://github.com/rust-lang/cargo/pull/15374/)
• [Use `gix` for `cargo package`](https://github.com/rust-lang/cargo/pull/15534/)
• [feat(publish): Stabilize multi-package publishing](https://github.com/rust-lang/cargo/pull/15636/)
• <a id="1.90-Rustdoc"></a>

📝 Rustdoc

• [Add ways to collapse all impl blocks](https://github.com/rust-lang/rust/pull/141663). Previously the "Summary" button and "-" keyboard shortcut would never collapse `impl` blocks, now they do when shift is held
• [Display unsafe attributes with `unsafe()` wrappers](https://github.com/rust-lang/rust/pull/143662)
• <a id="1.90-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Use `lld` by default on `x86_64-unknown-linux-gnu`](https://github.com/rust-lang/rust/pull/140525). See also <https://blog.rust-lang.org/2025/09/01/rust-lld-on-1.90.0-stable/>.
• [Make `core::iter::Fuse`'s `Default` impl construct `I::default()` internally as promised in the docs instead of always being empty](https://github.com/rust-lang/rust/pull/140985)
• [Set `MSG_NOSIGNAL` for `UnixStream`](https://github.com/rust-lang/rust/pull/140005) This may change program behavior but results in the same behavior as other primitives (e.g., stdout, network sockets). Programs relying on signals to terminate them should update handling of sockets to handle errors on write by exiting.
• [On Unix `std::env::home_dir` will use the fallback if the `HOME` environment variable is empty](https://github.com/rust-lang/rust/pull/141840)
• We now [reject unsupported `extern "{abi}"`s consistently in all positions](https://github.com/rust-lang/rust/pull/142134). This primarily affects the use of implementing traits on an `extern "{abi}"` function pointer, like `extern "stdcall" fn()`, on a platform that doesn't support that, like aarch64-unknown-linux-gnu. Direct usage of these unsupported ABI strings by declaring or defining functions was already rejected, so this is only a change for consistency.
• [const-eval: error when initializing a static writes to that static](https://github.com/rust-lang/rust/pull/143084)
• [Check that the `proc_macro_derive` macro has correct arguments when applied to the crate root](https://github.com/rust-lang/rust/pull/143607)

📦 Language

• [Stabilize explicitly inferred const arguments (`feature(generic_arg_infer)`)](https://github.com/rust-lang/rust/pull/141610)
• [Add a warn-by-default `mismatched_lifetime_syntaxes` lint.](https://github.com/rust-lang/rust/pull/138677) This lint detects when the same lifetime is referred to by different syntax categories between function arguments and return values, which can be confusing to read, especially in unsafe code. This lint supersedes the warn-by-default `elided_named_lifetimes` lint.
• [Expand `unpredictable_function_pointer_comparisons` to also lint on function pointer comparisons in external macros](https://github.com/rust-lang/rust/pull/134536)
• [Make the `dangerous_implicit_autorefs` lint deny-by-default](https://github.com/rust-lang/rust/pull/141661)
• [Stabilize the avx512 target features](https://github.com/rust-lang/rust/pull/138940)
• [Stabilize `kl` and `widekl` target features for x86](https://github.com/rust-lang/rust/pull/140766)
• [Stabilize `sha512`, `sm3` and `sm4` target features for x86](https://github.com/rust-lang/rust/pull/140767)
• [Stabilize LoongArch target features `f`, `d`, `frecipe`, `lasx`, `lbt`, `lsx`, and `lvz`](https://github.com/rust-lang/rust/pull/135015)
• + 6 more

📦 Compiler

• [Default to non-leaf frame pointers on aarch64-linux](https://github.com/rust-lang/rust/pull/140832)
• [Enable non-leaf frame pointers for Arm64EC Windows](https://github.com/rust-lang/rust/pull/140862)
• [Set Apple frame pointers by architecture](https://github.com/rust-lang/rust/pull/141797)
• <a id="1.89.0-Platform-Support"></a>

📦 Platform Support

• [Add new Tier-3 targets `loongarch32-unknown-none` and `loongarch32-unknown-none-softfloat`](https://github.com/rust-lang/rust/pull/142053)
• [`x86_64-apple-darwin` is in the process of being demoted to Tier 2 with host tools](https://github.com/rust-lang/rfcs/pull/3841)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.89.0-Libraries"></a>

📦 Libraries

• [Specify the base path for `file!`](https://github.com/rust-lang/rust/pull/134442)
• [Allow storing `format_args!()` in a variable](https://github.com/rust-lang/rust/pull/140748)
• [Add `#[must_use]` to `[T; N]::map`](https://github.com/rust-lang/rust/pull/140957)
• [Implement `DerefMut` for `Lazy{Cell,Lock}`](https://github.com/rust-lang/rust/pull/129334)
• [Implement `Default` for `array::IntoIter`](https://github.com/rust-lang/rust/pull/141574)
• [Implement `Clone` for `slice::ChunkBy`](https://github.com/rust-lang/rust/pull/138016)
• [Implement `io::Seek` for `io::Take`](https://github.com/rust-lang/rust/pull/138023)
• <a id="1.89.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`NonZero<char>`](https://doc.rust-lang.org/stable/std/num/struct.NonZero.html)
• Many intrinsics for x86, not enumerated here
• [AVX512 intrinsics](https://github.com/rust-lang/rust/issues/111137)
• [`SHA512`, `SM3` and `SM4` intrinsics](https://github.com/rust-lang/rust/issues/126624)
• [`File::lock`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.lock)
• [`File::lock_shared`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.lock_shared)
• [`File::try_lock`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.try_lock)
• [`File::try_lock_shared`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.try_lock_shared)
• + 16 more

📦 Cargo

• [`cargo fix` and `cargo clippy --fix` now default to the same Cargo target selection as other build commands.](https://github.com/rust-lang/cargo/pull/15192/) Previously it would apply to all targets (like binaries, examples, tests, etc.). The `--edition` flag still applies to all targets.
• [Stabilize doctest-xcompile.](https://github.com/rust-lang/cargo/pull/15462/) Doctests are now tested when cross-compiling. Just like other tests, it will use the [`runner` setting](https://doc.rust-lang.org/cargo/reference/config.html#targettriplerunner) to run the tests. If you need to disable tests for a target, you can use the [ignore doctest attribute](https://doc.rust-lang.org/rustdoc/write-documentation/documentation-tests.html#ignoring-targets) to specify the targets to ignore.
• <a id="1.89.0-Rustdoc"></a>

📝 Rustdoc

• [On mobile, make the sidebar full width and linewrap](https://github.com/rust-lang/rust/pull/139831). This makes long section and item names much easier to deal with on mobile.
• <a id="1.89.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Make `missing_fragment_specifier` an unconditional error](https://github.com/rust-lang/rust/pull/128425)
• [Enabling the `neon` target feature on `aarch64-unknown-none-softfloat` causes a warning](https://github.com/rust-lang/rust/pull/135160) because mixing code with and without that target feature is not properly supported by LLVM
• [Sized Hierarchy: Part I](https://github.com/rust-lang/rust/pull/137944)
• Introduces a small breaking change affecting `?Sized` bounds on impls on recursive types which contain associated type projections. It is not expected to affect any existing published crates. Can be fixed by refactoring the involved types or opting into the `sized_hierarchy` unstable feature. See the [FCP report](https://github.com/rust-lang/rust/pull/137944#issuecomment-2912207485) for a code example.
• The warn-by-default `elided_named_lifetimes` lint is [superseded by the warn-by-default `mismatched_lifetime_syntaxes` lint.](https://github.com/rust-lang/rust/pull/138677)
• [Error on recursive opaque types earlier in the type checker](https://github.com/rust-lang/rust/pull/139419)
• [Type inference side effects from requiring element types of array repeat expressions are `Copy` are now only available at the end of type checking](https://github.com/rust-lang/rust/pull/139635)
• [The deprecated accidentally-stable `std::intrinsics::{copy,copy_nonoverlapping,write_bytes}` are now proper intrinsics](https://github.com/rust-lang/rust/pull/139916). There are no debug assertions guarding against UB, and they cannot be coerced to function pointers.
• + 9 more

📋 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.
• [Correctly un-remap compiler sources paths with the `rustc-dev` component](https://github.com/rust-lang/rust/pull/142377)

📦 Language

• [Stabilize `#![feature(let_chains)]` in the 2024 edition.](https://github.com/rust-lang/rust/pull/132833) This feature allows `&&`-chaining `let` statements inside `if` and `while`, allowing intermixture with boolean expressions. The patterns inside the `let` sub-expressions can be irrefutable or refutable.
• [Stabilize `#![feature(naked_functions)]`.](https://github.com/rust-lang/rust/pull/134213) Naked functions allow writing functions with no compiler-generated epilogue and prologue, allowing full control over the generated assembly for a particular function.
• [Stabilize `#![feature(cfg_boolean_literals)]`.](https://github.com/rust-lang/rust/pull/138632) This allows using boolean literals as `cfg` predicates, e.g. `#[cfg(true)]` and `#[cfg(false)]`.
• [Fully de-stabilize the `#[bench]` attribute](https://github.com/rust-lang/rust/pull/134273). Usage of `#[bench]` without `#![feature(custom_test_frameworks)]` already triggered a deny-by-default future-incompatibility lint since Rust 1.77, but will now become a hard error.
• [Add warn-by-default `dangerous_implicit_autorefs` lint against implicit autoref of raw pointer dereference.](https://github.com/rust-lang/rust/pull/123239) The lint [will be bumped to deny-by-default](https://github.com/rust-lang/rust/pull/141661) in the next version of Rust.
• [Add `invalid_null_arguments` lint to prevent invalid usage of null pointers.](https://github.com/rust-lang/rust/pull/119220) This lint is uplifted from `clippy::invalid_null_ptr_usage`.
• [Change trait impl candidate preference for builtin impls and trivial where-clauses.](https://github.com/rust-lang/rust/pull/138176)
• [Check types of generic const parameter defaults](https://github.com/rust-lang/rust/pull/139646)
• + 1 more

📦 Compiler

• [Stabilize `-Cdwarf-version` for selecting the version of DWARF debug information to generate.](https://github.com/rust-lang/rust/pull/136926)
• <a id="1.88.0-Platform-Support"></a>

📦 Platform Support

• [Demote `i686-pc-windows-gnu` to Tier 2.](https://blog.rust-lang.org/2025/05/26/demoting-i686-pc-windows-gnu/)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.88.0-Libraries"></a>

📦 Libraries

• [Remove backticks from `#[should_panic]` test failure message.](https://github.com/rust-lang/rust/pull/136160)
• [Guarantee that `[T; N]::from_fn` is generated in order of increasing indices.](https://github.com/rust-lang/rust/pull/139099), for those passing it a stateful closure.
• [The libtest flag `--nocapture` is deprecated in favor of the more consistent `--no-capture` flag.](https://github.com/rust-lang/rust/pull/139224)
• [Guarantee that `{float}::NAN` is a quiet NaN.](https://github.com/rust-lang/rust/pull/139483)
• <a id="1.88.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`Cell::update`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.update)
• [`impl Default for *const T`](https://doc.rust-lang.org/stable/std/primitive.pointer.html#impl-Default-for-*const+T)
• [`impl Default for *mut T`](https://doc.rust-lang.org/stable/std/primitive.pointer.html#impl-Default-for-*mut+T)
• [`HashMap::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html#method.extract_if)
• [`HashSet::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.HashSet.html#method.extract_if)
• [`hint::select_unpredictable`](https://doc.rust-lang.org/stable/std/hint/fn.select_unpredictable.html)
• [`proc_macro::Span::line`](https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.line)
• [`proc_macro::Span::column`](https://doc.rust-lang.org/stable/proc_macro/struct.Span.html#method.column)
• + 21 more

📦 Cargo

• [Stabilize automatic garbage collection.](https://github.com/rust-lang/cargo/pull/14287/)
• [use `zlib-rs` for gzip compression in rust code](https://github.com/rust-lang/cargo/pull/15417/)
• <a id="1.88.0-Rustdoc"></a>

📝 Rustdoc

• [Doctests can be ignored based on target names using `ignore-*` attributes.](https://github.com/rust-lang/rust/pull/137096)
• [Stabilize the `--test-runtool` and `--test-runtool-arg` CLI options to specify a program (like qemu) and its arguments to run a doctest.](https://github.com/rust-lang/rust/pull/137096)
• <a id="1.88.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Finish changing the internal representation of pasted tokens](https://github.com/rust-lang/rust/pull/124141). Certain invalid declarative macros that were previously accepted in obscure circumstances are now correctly rejected by the compiler. Use of a `tt` fragment specifier can often fix these macros.
• [Fully de-stabilize the `#[bench]` attribute](https://github.com/rust-lang/rust/pull/134273). Usage of `#[bench]` without `#![feature(custom_test_frameworks)]` already triggered a deny-by-default future-incompatibility lint since Rust 1.77, but will now become a hard error.
• [Fix borrow checking some always-true patterns.](https://github.com/rust-lang/rust/pull/139042) The borrow checker was overly permissive in some cases, allowing programs that shouldn't have compiled.
• [Update the minimum external LLVM to 19.](https://github.com/rust-lang/rust/pull/139275)
• [Make it a hard error to use a vector type with a non-Rust ABI without enabling the required target feature.](https://github.com/rust-lang/rust/pull/139309)

📦 Language

• [Stabilize `asm_goto` feature](https://github.com/rust-lang/rust/pull/133870)
• [Allow parsing open beginning ranges (`..EXPR`) after unary operators `!`, `-`, and `*`](https://github.com/rust-lang/rust/pull/134900).
• [Don't require method impls for methods with `Self: Sized` bounds in `impl`s for unsized types](https://github.com/rust-lang/rust/pull/135480)
• [Stabilize `feature(precise_capturing_in_traits)` allowing `use<...>` bounds on return position `impl Trait` in `trait`s](https://github.com/rust-lang/rust/pull/138128)
• <a id="1.87.0-Compiler"></a>

📦 Compiler

• [x86: make SSE2 required for i686 targets and use it to pass SIMD types](https://github.com/rust-lang/rust/pull/135408)
• <a id="1.87.0-Platform-Support"></a>

📦 Platform Support

• [Remove `i586-pc-windows-msvc` target](https://github.com/rust-lang/rust/pull/137957)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.87.0-Libraries"></a>

📦 Libraries

• [Stabilize the anonymous pipe API](https://github.com/rust-lang/rust/issues/127154)
• [Add support for unbounded left/right shift operations](https://github.com/rust-lang/rust/issues/129375)
• [Print pointer metadata in `Debug` impl of raw pointers](https://github.com/rust-lang/rust/pull/135080)
• [`Vec::with_capacity` guarantees it allocates with the amount requested, even if `Vec::capacity` returns a different number.](https://github.com/rust-lang/rust/pull/135933)
• Most `std::arch` intrinsics which don't take pointer arguments can now be called from safe code if the caller has the appropriate target features already enabled (https://github.com/rust-lang/stdarch/pull/1714, https://github.com/rust-lang/stdarch/pull/1716, https://github.com/rust-lang/stdarch/pull/1717)
• [Undeprecate `env::home_dir`](https://github.com/rust-lang/rust/pull/137327)
• [Denote `ControlFlow` as `#[must_use]`](https://github.com/rust-lang/rust/pull/137449)
• [Macros such as `assert_eq!` and `vec!` now support `const {...}` expressions](https://github.com/rust-lang/rust/pull/138162)
• + 1 more

📦 Stabilized APIs

• [`Vec::extract_if`](https://doc.rust-lang.org/stable/std/vec/struct.Vec.html#method.extract_if)
• [`vec::ExtractIf`](https://doc.rust-lang.org/stable/std/vec/struct.ExtractIf.html)
• [`LinkedList::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.LinkedList.html#method.extract_if)
• [`linked_list::ExtractIf`](https://doc.rust-lang.org/stable/std/collections/linked_list/struct.ExtractIf.html)
• [`<[T]>::split_off`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_off)
• [`<[T]>::split_off_mut`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_off_mut)
• [`<[T]>::split_off_first`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_off_first)
• [`<[T]>::split_off_first_mut`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.split_off_first_mut)
• + 68 more

📦 Cargo

• [Add terminal integration via ANSI OSC 9;4 sequences](https://github.com/rust-lang/cargo/pull/14615/)
• [chore: bump openssl to v3](https://github.com/rust-lang/cargo/pull/15232/)
• [feat(package): add --exclude-lockfile flag](https://github.com/rust-lang/cargo/pull/15234/)
• <a id="1.87.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Rust now raises an error for macro invocations inside the `#![crate_name]` attribute](https://github.com/rust-lang/rust/pull/127581)
• [Unstable fields are now always considered to be inhabited](https://github.com/rust-lang/rust/pull/133889)
• [Macro arguments of unary operators followed by open beginning ranges may now be matched differently](https://github.com/rust-lang/rust/pull/134900)
• [Make `Debug` impl of raw pointers print metadata if present](https://github.com/rust-lang/rust/pull/135080)
• [Warn against function pointers using unsupported ABI strings in dependencies](https://github.com/rust-lang/rust/pull/135767)
• [Associated types on `dyn` types are no longer deduplicated](https://github.com/rust-lang/rust/pull/136458)
• [Forbid attributes on `..` inside of struct patterns (`let Struct { #[attribute] .. }) =`](https://github.com/rust-lang/rust/pull/136490)
• [Make `ptr_cast_add_auto_to_object` lint into hard error](https://github.com/rust-lang/rust/pull/136764)
• + 9 more

📋 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.
• [Update to LLVM 20](https://github.com/rust-lang/rust/pull/135763)

📦 Language

• [Stabilize upcasting trait objects to supertraits.](https://github.com/rust-lang/rust/pull/134367)
• [Allow safe functions to be marked with the `#[target_feature]` attribute.](https://github.com/rust-lang/rust/pull/134090)
• [The `missing_abi` lint now warns-by-default.](https://github.com/rust-lang/rust/pull/132397)
• Rust now lints about double negations, to catch cases that might have intended to be a prefix decrement operator (`--x`) as written in other languages. This was previously a clippy lint, `clippy::double_neg`, and is [now available directly in Rust as `double_negations`.](https://github.com/rust-lang/rust/pull/126604)
• [More pointers are now detected as definitely not-null based on their alignment in const eval.](https://github.com/rust-lang/rust/pull/133700)
• [Empty `repr()` attribute applied to invalid items are now correctly rejected.](https://github.com/rust-lang/rust/pull/133925)
• [Inner attributes `#![test]` and `#![rustfmt::skip]` are no longer accepted in more places than intended.](https://github.com/rust-lang/rust/pull/134276)
• <a id="1.86.0-Compiler"></a>

📦 Compiler

• [Debug-assert that raw pointers are non-null on access.](https://github.com/rust-lang/rust/pull/134424)
• [Change `-O` to mean `-C opt-level=3` instead of `-C opt-level=2` to match Cargo's defaults.](https://github.com/rust-lang/rust/pull/135439)
• [Fix emission of `overflowing_literals` under certain macro environments.](https://github.com/rust-lang/rust/pull/136393)
• <a id="1.86.0-Platform-Support"></a>

📦 Platform Support

• [Replace `i686-unknown-redox` target with `i586-unknown-redox`.](https://github.com/rust-lang/rust/pull/136698)
• [Increase baseline CPU of `i686-unknown-hurd-gnu` to Pentium 4.](https://github.com/rust-lang/rust/pull/136700)
• New tier 3 targets:
• [`{aarch64-unknown,x86_64-pc}-nto-qnx710_iosock`](https://github.com/rust-lang/rust/pull/133631). For supporting Neutrino QNX 7.1 with `io-socket` network stack.
• [`{aarch64-unknown,x86_64-pc}-nto-qnx800`](https://github.com/rust-lang/rust/pull/133631). For supporting Neutrino QNX 8.0 (`no_std`-only).
• [`{x86_64,i686}-win7-windows-gnu`](https://github.com/rust-lang/rust/pull/134609). Intended for backwards compatibility with Windows 7. `{x86_64,i686}-win7-windows-msvc` are the Windows MSVC counterparts that already exist as Tier 3 targets.
• [`amdgcn-amd-amdhsa`](https://github.com/rust-lang/rust/pull/134740).
• [`x86_64-pc-cygwin`](https://github.com/rust-lang/rust/pull/134999).
• + 5 more

📦 Libraries

• The type of `FromBytesWithNulError` in `CStr::from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, FromBytesWithNulError>` was [changed from an opaque struct to an enum](https://github.com/rust-lang/rust/pull/134143), allowing users to examine why the conversion failed.
• [Remove `RustcDecodable` and `RustcEncodable`.](https://github.com/rust-lang/rust/pull/134272)
• [Deprecate libtest's `--logfile` option.](https://github.com/rust-lang/rust/pull/134283)
• [On recent versions of Windows, `std::fs::remove_file` will now remove read-only files.](https://github.com/rust-lang/rust/pull/134679)
• <a id="1.86.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`{float}::next_down`](https://doc.rust-lang.org/stable/std/primitive.f64.html#method.next_down)
• [`{float}::next_up`](https://doc.rust-lang.org/stable/std/primitive.f64.html#method.next_up)
• [`<[_]>::get_disjoint_mut`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.get_disjoint_mut)
• [`<[_]>::get_disjoint_unchecked_mut`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.get_disjoint_unchecked_mut)
• [`slice::GetDisjointMutError`](https://doc.rust-lang.org/stable/std/slice/enum.GetDisjointMutError.html)
• [`HashMap::get_disjoint_mut`](https://doc.rust-lang.org/std/collections/hash_map/struct.HashMap.html#method.get_disjoint_mut)
• [`HashMap::get_disjoint_unchecked_mut`](https://doc.rust-lang.org/std/collections/hash_map/struct.HashMap.html#method.get_disjoint_unchecked_mut)
• [`NonZero::count_ones`](https://doc.rust-lang.org/stable/std/num/struct.NonZero.html#method.count_ones)
• + 14 more

📦 Cargo

• [When merging, replace rather than combine configuration keys that refer to a program path and its arguments.](https://github.com/rust-lang/cargo/pull/15066/)
• [Error if both `--package` and `--workspace` are passed but the requested package is missing.](https://github.com/rust-lang/cargo/pull/15071/) This was previously silently ignored, which was considered a bug since missing packages should be reported.
• [Deprecate the token argument in `cargo login` to avoid shell history leaks.](https://github.com/rust-lang/cargo/pull/15057/)
• [Simplify the implementation of `SourceID` comparisons.](https://github.com/rust-lang/cargo/pull/14980/) This may potentially change behavior if the canonicalized URL compares differently in alternative registries.
• <a id="1.86.0-Rustdoc"></a>

📝 Rustdoc

• [Add a sans-serif font setting.](https://github.com/rust-lang/rust/pull/133636)
• <a id="1.86.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [The `wasm_c_abi` future compatibility warning is now a hard error.](https://github.com/rust-lang/rust/pull/133951) Users of `wasm-bindgen` should upgrade to at least version 0.2.89, otherwise compilation will fail.
• [Remove long-deprecated no-op attributes `#![no_start]` and `#![crate_id]`.](https://github.com/rust-lang/rust/pull/134300)
• [The future incompatibility lint `cenum_impl_drop_cast` has been made into a hard error.](https://github.com/rust-lang/rust/pull/135964) This means it is now an error to cast a field-less enum to an integer if the enum implements `Drop`.
• [SSE2 is now required for "i686" 32-bit x86 hard-float targets; disabling it causes a warning that will become a hard error eventually.](https://github.com/rust-lang/rust/pull/137037) To compile for pre-SSE2 32-bit x86, use a "i586" target instead.
• <a id="1.86.0-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.
• [Build the rustc on AArch64 Linux with ThinLTO + PGO.](https://github.com/rust-lang/rust/pull/133807) The ARM 64-bit compiler (AArch64) on Linux is now optimized with ThinLTO and PGO, similar to the optimizations we have already performed for the x86-64 compiler on Linux. This should make it up to 30% faster.

📋 Changes

• [Fix the doctest-merging feature of the 2024 Edition.](https://github.com/rust-lang/rust/pull/137899/)
• [Relax some `target_feature` checks when generating docs.](https://github.com/rust-lang/rust/pull/137632/)
• [Fix errors in `std::fs::rename` on Windows 10, version 1607.](https://github.com/rust-lang/rust/pull/137528/)
• [Downgrade bootstrap `cc` to fix custom targets.](https://github.com/rust-lang/rust/pull/137460/)
• [Skip submodule updates when building Rust from a source tarball.](https://github.com/rust-lang/rust/pull/137338/)

📦 Language

• [The 2024 Edition is now stable.](https://github.com/rust-lang/rust/pull/133349) See [the edition guide](https://doc.rust-lang.org/nightly/edition-guide/rust-2024/index.html) for more details.
• [Stabilize async closures](https://github.com/rust-lang/rust/pull/132706) See [RFC 3668](https://rust-lang.github.io/rfcs/3668-async-closures.html) for more details.
• [Stabilize `#[diagnostic::do_not_recommend]`](https://github.com/rust-lang/rust/pull/132056)
• [Add `unpredictable_function_pointer_comparisons` lint to warn against function pointer comparisons](https://github.com/rust-lang/rust/pull/118833)
• [Lint on combining `#[no_mangle]` and `#[export_name]` attributes.](https://github.com/rust-lang/rust/pull/131558)
• <a id="1.85.0-Compiler"></a>

📦 Compiler

• [The unstable flag `-Zpolymorphize` has been removed](https://github.com/rust-lang/rust/pull/133883), see https://github.com/rust-lang/compiler-team/issues/810 for some background.
• <a id="1.85.0-Platform-Support"></a>

📦 Platform Support

• [Promote `powerpc64le-unknown-linux-musl` to tier 2 with host tools](https://github.com/rust-lang/rust/pull/133801)
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.85.0-Libraries"></a>

📦 Libraries

• [Panics in the standard library now have a leading `library/` in their path](https://github.com/rust-lang/rust/pull/132390)
• [`std::env::home_dir()` on Windows now ignores the non-standard `$HOME` environment variable](https://github.com/rust-lang/rust/pull/132515)
• It will be un-deprecated in a subsequent release.
• [Add `AsyncFn*` to the prelude in all editions.](https://github.com/rust-lang/rust/pull/132611)
• <a id="1.85.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`BuildHasherDefault::new`](https://doc.rust-lang.org/stable/std/hash/struct.BuildHasherDefault.html#method.new)
• [`ptr::fn_addr_eq`](https://doc.rust-lang.org/std/ptr/fn.fn_addr_eq.html)
• [`io::ErrorKind::QuotaExceeded`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.QuotaExceeded)
• [`io::ErrorKind::CrossesDevices`](https://doc.rust-lang.org/stable/std/io/enum.ErrorKind.html#variant.CrossesDevices)
• [`{float}::midpoint`](https://doc.rust-lang.org/core/primitive.f32.html#method.midpoint)
• [Unsigned `{integer}::midpoint`](https://doc.rust-lang.org/std/primitive.u64.html#method.midpoint)
• [`NonZeroU*::midpoint`](https://doc.rust-lang.org/std/num/type.NonZeroU32.html#method.midpoint)
• [impl `std::iter::Extend` for tuples with arity 1 through 12](https://doc.rust-lang.org/stable/std/iter/trait.Extend.html#impl-Extend%3C\(A,\)%3E-for-\(EA,\))
• + 27 more

📦 Cargo

• [Add future-incompatibility warning against keywords in cfgs and add raw-idents](https://github.com/rust-lang/cargo/pull/14671/)
• [Stabilize higher precedence trailing flags](https://github.com/rust-lang/cargo/pull/14900/)
• [Pass `CARGO_CFG_FEATURE` to build scripts](https://github.com/rust-lang/cargo/pull/14902/)
• <a id="1.85.0-Rustdoc"></a>

📝 Rustdoc

• [Doc comment on impl blocks shows the first line, even when the impl block is collapsed](https://github.com/rust-lang/rust/pull/132155)
• <a id="1.85.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [`rustc` no longer treats the `test` cfg as a well known check-cfg](https://github.com/rust-lang/rust/pull/131729), instead it is up to the build systems and users of `--check-cfg`\[^check-cfg\] to set it as a well known cfg using `--check-cfg=cfg(test)`.
• [Disable potentially incorrect type inference if there are trivial and non-trivial where-clauses](https://github.com/rust-lang/rust/pull/132325)
• `std::env::home_dir()` has been deprecated for years, because it can give surprising results in some Windows configurations if the `HOME` environment variable is set (which is not the normal configuration on Windows). We had previously avoided changing its behavior, out of concern for compatibility with code depending on this non-standard configuration. Given how long this function has been deprecated, we're now fixing its behavior as a bugfix. A subsequent release will remove the deprecation for this function.
• [Make `core::ffi::c_char` signedness more closely match that of the platform-default `char`](https://github.com/rust-lang/rust/pull/132975)
• The `libc` crate matches this change as of its 0.2.169 release.
• [When compiling a nested `macro_rules` macro from an external crate, the content of the inner `macro_rules` is now built with the edition of the external crate, not the local crate.](https://github.com/rust-lang/rust/pull/133274)
• [Increase `sparcv9-sun-solaris` and `x86_64-pc-solaris` Solaris baseline to 11.4.](https://github.com/rust-lang/rust/pull/133293)
• [Show `abi_unsupported_vector_types` lint in future breakage reports](https://github.com/rust-lang/rust/pull/133374)
• + 3 more

📋 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.
• [Build `x86_64-unknown-linux-gnu` with LTO for C/C++ code (e.g., `jemalloc`)](https://github.com/rust-lang/rust/pull/134690)

📋 Changes

• [Fix ICE 132920 in duplicate-crate diagnostics.](https://github.com/rust-lang/rust/pull/133304/)
• [Fix errors for overlapping impls in incremental rebuilds.](https://github.com/rust-lang/rust/pull/133828/)
• [Fix slow compilation related to the next-generation trait solver.](https://github.com/rust-lang/rust/pull/135618/)
• [Fix debuginfo when LLVM's location discriminator value limit is exceeded.](https://github.com/rust-lang/rust/pull/135643/)
• Fixes for building Rust from source:
• [Only try to distribute `llvm-objcopy` if llvm tools are enabled.](https://github.com/rust-lang/rust/pull/134240/)
• [Add Profile Override for Non-Git Sources.](https://github.com/rust-lang/rust/pull/135433/)
• [Resolve symlinks of LLVM tool binaries before copying them.](https://github.com/rust-lang/rust/pull/135585/)
• + 1 more

📦 Language

• [Allow `#[deny]` inside `#[forbid]` as a no-op](https://github.com/rust-lang/rust/pull/121560/)
• [Show a warning when `-Ctarget-feature` is used to toggle features that can lead to unsoundness due to ABI mismatches](https://github.com/rust-lang/rust/pull/129884)
• [Use the next-generation trait solver in coherence](https://github.com/rust-lang/rust/pull/130654)
• [Allow coercions to drop the principal of trait objects](https://github.com/rust-lang/rust/pull/131857)
• [Support `/` as the path separator for `include!()` in all cases on Windows](https://github.com/rust-lang/rust/pull/125205)
• [Taking a raw ref (`raw (const|mut)`) of a deref of a pointer (`*ptr`) is now safe](https://github.com/rust-lang/rust/pull/129248)
• [Stabilize s390x inline assembly](https://github.com/rust-lang/rust/pull/131258)
• [Stabilize Arm64EC inline assembly](https://github.com/rust-lang/rust/pull/131781)
• + 3 more

📦 Compiler

• [Add `--print host-tuple` flag to print the host target tuple and affirm the "target tuple" terminology over "target triple"](https://github.com/rust-lang/rust/pull/125579)
• [Declaring functions with a calling convention not supported on the current target now triggers a hard error](https://github.com/rust-lang/rust/pull/129935)
• [Set up indirect access to external data for `loongarch64-unknown-linux-{musl,ohos}`](https://github.com/rust-lang/rust/pull/131583)
• [Enable XRay instrumentation for LoongArch Linux targets](https://github.com/rust-lang/rust/pull/131818)
• [Extend the `unexpected_cfgs` lint to also warn in external macros](https://github.com/rust-lang/rust/pull/132577)
• [Stabilize WebAssembly `multivalue`, `reference-types`, and `tail-call` target features](https://github.com/rust-lang/rust/pull/131080)
• [Added Tier 2 support for the `wasm32v1-none` target](https://github.com/rust-lang/rust/pull/131487)
• <a id="1.84.0-Libraries"></a>

📦 Libraries

• [Implement `From<&mut {slice}>` for `Box/Rc/Arc<{slice}>`](https://github.com/rust-lang/rust/pull/129329)
• [Move `<float>::copysign`, `<float>::abs`, `<float>::signum` to `core`](https://github.com/rust-lang/rust/pull/131304)
• [Add `LowerExp` and `UpperExp` implementations to `NonZero`](https://github.com/rust-lang/rust/pull/131377)
• [Implement `FromStr` for `CString` and `TryFrom<CString>` for `String`](https://github.com/rust-lang/rust/pull/130608)
• [`std::os::darwin` has been made public](https://github.com/rust-lang/rust/pull/123723)
• <a id="1.84.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`Ipv6Addr::is_unique_local`](https://doc.rust-lang.org/stable/core/net/struct.Ipv6Addr.html#method.is_unique_local)
• [`Ipv6Addr::is_unicast_link_local`](https://doc.rust-lang.org/stable/core/net/struct.Ipv6Addr.html#method.is_unicast_link_local)
• [`core::ptr::with_exposed_provenance`](https://doc.rust-lang.org/stable/core/ptr/fn.with_exposed_provenance.html)
• [`core::ptr::with_exposed_provenance_mut`](https://doc.rust-lang.org/stable/core/ptr/fn.with_exposed_provenance_mut.html)
• [`<ptr>::addr`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.addr)
• [`<ptr>::expose_provenance`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.expose_provenance)
• [`<ptr>::with_addr`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.with_addr)
• [`<ptr>::map_addr`](https://doc.rust-lang.org/stable/core/primitive.pointer.html#method.map_addr)
• + 34 more

📦 Cargo

• [Stabilize MSRV-aware resolver config](https://github.com/rust-lang/cargo/pull/14639/)
• [Stabilize resolver v3](https://github.com/rust-lang/cargo/pull/14754/)
• <a id="1.84-Rustdoc"></a>

📝 Rustdoc

• [rustdoc-search: improve type-driven search](https://github.com/rust-lang/rust/pull/127589)
• <a id="1.84.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Enable by default the `LSX` target feature for LoongArch Linux targets](https://github.com/rust-lang/rust/pull/132140)
• [The unstable `-Zprofile` flag (“gcov-style” coverage instrumentation) has been removed.](https://github.com/rust-lang/rust/pull/131829) This does not affect the stable flags for coverage instrumentation (`-Cinstrument-coverage`) and profile-guided optimization (`-Cprofile-generate`, `-Cprofile-use`), which are unrelated and remain available.
• Support for the target named `wasm32-wasi` has been removed as the target is now named `wasm32-wasip1`. This completes the [transition](https://github.com/rust-lang/compiler-team/issues/607) [plan](https://github.com/rust-lang/compiler-team/issues/695) for this target following [the introduction of `wasm32-wasip1`](https://github.com/rust-lang/rust/pull/120468) in Rust 1.78. Compiler warnings on [use of `wasm32-wasi`](https://github.com/rust-lang/rust/pull/126662) introduced in Rust 1.81 are now gone as well as the target is removed.
• [The syntax `&pin (mut|const) T` is now parsed as a type which in theory could affect macro expansion results in some edge cases](https://github.com/rust-lang/rust/pull/130635#issuecomment-2375462821)
• [Legacy syntax for calling `std::arch` functions is no longer permitted to declare items or bodies (such as closures, inline consts, or async blocks).](https://github.com/rust-lang/rust/pull/130443#issuecomment-2445678945)
• [Declaring functions with a calling convention not supported on the current target now triggers a hard error](https://github.com/rust-lang/rust/pull/129935)
• [The next-generation trait solver is now enabled for coherence, fixing multiple soundness issues](https://github.com/rust-lang/rust/pull/130654)

📦 Language

• [Stabilize `&mut`, `*mut`, `&Cell`, and `*const Cell` in const.](https://github.com/rust-lang/rust/pull/129195)
• [Allow creating references to statics in `const` initializers.](https://github.com/rust-lang/rust/pull/129759)
• [Implement raw lifetimes and labels (`'r#ident`).](https://github.com/rust-lang/rust/pull/126452)
• [Define behavior when atomic and non-atomic reads race.](https://github.com/rust-lang/rust/pull/128778)
• [Non-exhaustive structs may now be empty.](https://github.com/rust-lang/rust/pull/128934)
• [Disallow implicit coercions from places of type `!`](https://github.com/rust-lang/rust/pull/129392)
• [`const extern` functions can now be defined for other calling conventions.](https://github.com/rust-lang/rust/pull/129753)
• [Stabilize `expr_2021` macro fragment specifier in all editions.](https://github.com/rust-lang/rust/pull/129972)
• + 2 more

📦 Compiler

• [Deprecate unsound `-Csoft-float` flag.](https://github.com/rust-lang/rust/pull/129897)
• Add many new tier 3 targets:
• [`aarch64_unknown_nto_qnx700`](https://github.com/rust-lang/rust/pull/127897)
• [`arm64e-apple-tvos`](https://github.com/rust-lang/rust/pull/130614)
• [`armv7-rtems-eabihf`](https://github.com/rust-lang/rust/pull/127021)
• [`loongarch64-unknown-linux-ohos`](https://github.com/rust-lang/rust/pull/130750)
• [`riscv32-wrs-vxworks` and `riscv64-wrs-vxworks`](https://github.com/rust-lang/rust/pull/130549)
• [`riscv32{e|em|emc}-unknown-none-elf`](https://github.com/rust-lang/rust/pull/130555)
• + 4 more

📦 Libraries

• [Implement `PartialEq` for `ExitCode`.](https://github.com/rust-lang/rust/pull/127633)
• [Document that `catch_unwind` can deal with foreign exceptions without UB, although the exact behavior is unspecified.](https://github.com/rust-lang/rust/pull/128321)
• [Implement `Default` for `HashMap`/`HashSet` iterators that don't already have it.](https://github.com/rust-lang/rust/pull/128711)
• [Bump Unicode to version 16.0.0.](https://github.com/rust-lang/rust/pull/130183)
• [Change documentation of `ptr::add`/`sub` to not claim equivalence with `offset`.](https://github.com/rust-lang/rust/pull/130229)
• <a id="1.83.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`BufRead::skip_until`](https://doc.rust-lang.org/stable/std/io/trait.BufRead.html#method.skip_until)
• [`ControlFlow::break_value`](https://doc.rust-lang.org/stable/core/ops/enum.ControlFlow.html#method.break_value)
• [`ControlFlow::continue_value`](https://doc.rust-lang.org/stable/core/ops/enum.ControlFlow.html#method.continue_value)
• [`ControlFlow::map_break`](https://doc.rust-lang.org/stable/core/ops/enum.ControlFlow.html#method.map_break)
• [`ControlFlow::map_continue`](https://doc.rust-lang.org/stable/core/ops/enum.ControlFlow.html#method.map_continue)
• [`DebugList::finish_non_exhaustive`](https://doc.rust-lang.org/stable/core/fmt/struct.DebugList.html#method.finish_non_exhaustive)
• [`DebugMap::finish_non_exhaustive`](https://doc.rust-lang.org/stable/core/fmt/struct.DebugMap.html#method.finish_non_exhaustive)
• [`DebugSet::finish_non_exhaustive`](https://doc.rust-lang.org/stable/core/fmt/struct.DebugSet.html#method.finish_non_exhaustive)
• + 107 more

📦 Cargo

• [Introduced a new `CARGO_MANIFEST_PATH` environment variable, similar to `CARGO_MANIFEST_DIR` but pointing directly to the manifest file.](https://github.com/rust-lang/cargo/pull/14404/)
• [Added `package.autolib` to the manifest, allowing `[lib]` auto-discovery to be disabled.](https://github.com/rust-lang/cargo/pull/14591/)
• [Declare support level for each crate in Cargo's Charter / crate docs.](https://github.com/rust-lang/cargo/pull/14600/)
• [Declare new Intentional Artifacts as 'small' changes.](https://github.com/rust-lang/cargo/pull/14599/)
• <a id="1.83-Rustdoc"></a>

📝 Rustdoc

• [The sidebar / hamburger menu table of contents now includes the `# headers` from the main item's doc comment](https://github.com/rust-lang/rust/pull/120736). This is similar to a third-party feature provided by the rustdoc-search-enhancements browser extension.
• <a id="1.83.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Warn against function pointers using unsupported ABI strings.](https://github.com/rust-lang/rust/pull/128784)
• [Check well-formedness of the source type's signature in fn pointer casts.](https://github.com/rust-lang/rust/pull/129021) This partly closes a soundness hole that comes when casting a function item to function pointer
• [Use equality instead of subtyping when resolving type dependent paths.](https://github.com/rust-lang/rust/pull/129073)
• Linking on macOS now correctly includes Rust's default deployment target. Due to a linker bug, you might have to pass `MACOSX_DEPLOYMENT_TARGET` or fix your `#[link]` attributes to point to the correct frameworks. See <https://github.com/rust-lang/rust/pull/129369>.
• [Rust will now correctly raise an error for `repr(Rust)` written on non-`struct`/`enum`/`union` items, since it previously did not have any effect.](https://github.com/rust-lang/rust/pull/129422)
• The future incompatibility lint `deprecated_cfg_attr_crate_type_name` [has been made into a hard error](https://github.com/rust-lang/rust/pull/129670). It was used to deny usage of `#![crate_type]` and `#![crate_name]` attributes in `#![cfg_attr]`, which required a hack in the compiler to be able to change the used crate type and crate name after cfg expansion. Users can use `--crate-type` instead of `#![cfg_attr(..., crate_type = "...")]` and `--crate-name` instead of `#![cfg_attr(..., crate_name = "...")]` when running `rustc`/`cargo rustc` on the command line. Use of those two attributes outside of `#![cfg_attr]` continue to be fully supported.
• Until now, paths into the sysroot were always prefixed with `/rustc/$hash` in diagnostics, codegen, backtrace, e.g.
• thread 'main' panicked at 'hello world', map-panic.rs:2:50
• + 21 more

📦 Language

• [Don't make statement nonterminals match pattern nonterminals](https://github.com/rust-lang/rust/pull/120221/)
• [Patterns matching empty types can now be omitted in common cases](https://github.com/rust-lang/rust/pull/122792)
• [Enforce supertrait outlives obligations when using trait impls](https://github.com/rust-lang/rust/pull/124336)
• [`addr_of(_mut)!` macros and the newly stabilized `&raw (const|mut)` are now safe to use with all static items](https://github.com/rust-lang/rust/pull/125834)
• [size\_of\_val\_raw: for length 0 this is safe to call](https://github.com/rust-lang/rust/pull/126152/)
• [Reorder trait bound modifiers *after* `for<...>` binder in trait bounds](https://github.com/rust-lang/rust/pull/127054/)
• [Stabilize `+ use<'lt>` opaque type precise capturing (RFC 3617)](https://github.com/rust-lang/rust/pull/127672)
• [Stabilize `&raw const` and `&raw mut` operators (RFC 2582)](https://github.com/rust-lang/rust/pull/127679)
• + 8 more

📦 Compiler

• [Promote riscv64gc-unknown-linux-musl to tier 2](https://github.com/rust-lang/rust/pull/122049)
• [Promote Mac Catalyst targets `aarch64-apple-ios-macabi` and `x86_64-apple-ios-macabi` to Tier 2, and ship them with rustup](https://github.com/rust-lang/rust/pull/126450)
• [Add tier 3 NuttX based targets for RISC-V and ARM](https://github.com/rust-lang/rust/pull/127755)
• [Add tier 3 powerpc-unknown-linux-muslspe target](https://github.com/rust-lang/rust/pull/127905)
• [Improved diagnostics to explain why a pattern is unreachable](https://github.com/rust-lang/rust/pull/128034)
• [The compiler now triggers the unreachable code warning properly for async functions that don't return/are `-> !`](https://github.com/rust-lang/rust/pull/128443)
• [Promote `aarch64-apple-darwin` to Tier 1](https://github.com/rust-lang/rust/pull/128592)
• [Add Trusty OS target `aarch64-unknown-trusty` and `armv7-unknown-trusty` as tier 3 targets](https://github.com/rust-lang/rust/pull/129490)
• + 2 more

📦 Libraries

• [Generalize `{Rc,Arc}::make_mut()` to `Path`, `OsStr`, and `CStr`.](https://github.com/rust-lang/rust/pull/126877)
• <a id="1.82.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`std::thread::Builder::spawn_unchecked`](https://doc.rust-lang.org/stable/std/thread/struct.Builder.html#method.spawn_unchecked)
• [`std::str::CharIndices::offset`](https://doc.rust-lang.org/nightly/std/str/struct.CharIndices.html#method.offset)
• [`std::option::Option::is_none_or`](https://doc.rust-lang.org/nightly/std/option/enum.Option.html#method.is_none_or)
• [`[T]::is_sorted`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.is_sorted)
• [`[T]::is_sorted_by`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.is_sorted_by)
• [`[T]::is_sorted_by_key`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.is_sorted_by_key)
• [`Iterator::is_sorted`](https://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.is_sorted)
• [`Iterator::is_sorted_by`](https://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.is_sorted_by)
• + 70 more

📦 Cargo

• [feat: Add `info` cargo subcommand](https://github.com/rust-lang/cargo/pull/14141/)
• <a id="1.82.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• We now [disallow setting some built-in cfgs via the command-line](https://github.com/rust-lang/rust/pull/126158) with the newly added [`explicit_builtin_cfgs_in_flags`](https://doc.rust-lang.org/rustc/lints/listing/deny-by-default.html#explicit-builtin-cfgs-in-flags) lint in order to prevent incoherent state, eg. `windows` cfg active but target is Linux based. The appropriate [`rustc` flag](https://doc.rust-lang.org/rustc/command-line-arguments.html) should be used instead.
• The standard library has a new implementation of `binary_search` which significantly improves performance ([\#128254](https://github.com/rust-lang/rust/pull/128254)). However when a sorted slice has multiple values which compare equal, the new implementation may select a different value among the equal ones than the old implementation.
• [illumos/Solaris now sets `MSG_NOSIGNAL` when writing to sockets](https://github.com/rust-lang/rust/pull/128259). This avoids killing the process with SIGPIPE when writing to a closed socket, which matches the existing behavior on other UNIX targets.
• [Removes a problematic hack that always passed the --whole-archive linker flag for tests, which may cause linker errors for code accidentally relying on it.](https://github.com/rust-lang/rust/pull/128400)
• The WebAssembly target features `multivalue` and `reference-types` are now both enabled by default. These two features both have subtle changes implied for generated WebAssembly binaries. For the `multivalue` feature, WebAssembly target support has changed when upgrading to LLVM 19. Support for generating functions with multiple returns no longer works and `-Ctarget-feature=+multivalue` has a different meaning than it did in LLVM 18 and prior. There is no longer any supported means to generate a module that has a function with multiple returns in WebAssembly from Rust source code. For the `reference-types` feature the encoding of immediates in the `call_indirect`, a commonly used instruction by the WebAssembly backend, has changed. Validators and parsers which don't understand the `reference-types` proposal will no longer accept modules produced by LLVM due to this change in encoding of immediates. Additionally these features being enabled are encoded in the `target_features` custom section and may affect downstream tooling such as `wasm-opt` consuming the module. Generating a WebAssembly module that disables default features requires `-Zbuild-std` support from Cargo and more information can be found at [rust-lang/rust\#128511](https://github.com/rust-lang/rust/pull/128511).
• [Rust now raises unsafety errors for union patterns in parameter-position](https://github.com/rust-lang/rust/pull/130531)
• <a id="1.82.0-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.
• [Update to LLVM 19](https://github.com/rust-lang/rust/pull/127513)

📦 Language

• [Abort on uncaught panics in `extern "C"` functions.](https://github.com/rust-lang/rust/pull/116088/)
• [Fix ambiguous cases of multiple `&` in elided self lifetimes.](https://github.com/rust-lang/rust/pull/117967/)
• [Stabilize `#[expect]` for lints (RFC 2383),](https://github.com/rust-lang/rust/pull/120924/) like `#[allow]` with a warning if the lint is *not* fulfilled.
• [Change method resolution to constrain hidden types instead of rejecting method candidates.](https://github.com/rust-lang/rust/pull/123962/)
• [Bump `elided_lifetimes_in_associated_constant` to deny.](https://github.com/rust-lang/rust/pull/124211/)
• [`offset_from`: always allow pointers to point to the same address.](https://github.com/rust-lang/rust/pull/124921/)
• [Allow constraining opaque types during subtyping in the trait system.](https://github.com/rust-lang/rust/pull/125447/)
• [Allow constraining opaque types during various unsizing casts.](https://github.com/rust-lang/rust/pull/125610/)
• + 2 more

📦 Compiler

• [Make casts of pointers to trait objects stricter.](https://github.com/rust-lang/rust/pull/120248/)
• [Check alias args for well-formedness even if they have escaping bound vars.](https://github.com/rust-lang/rust/pull/123737/)
• [Deprecate no-op codegen option `-Cinline-threshold=...`.](https://github.com/rust-lang/rust/pull/124712/)
• [Re-implement a type-size based limit.](https://github.com/rust-lang/rust/pull/125507/)
• [Properly account for alignment in `transmute` size checks.](https://github.com/rust-lang/rust/pull/125740/)
• [Remove the `box_pointers` lint.](https://github.com/rust-lang/rust/pull/126018/)
• [Ensure the interpreter checks bool/char for validity when they are used in a cast.](https://github.com/rust-lang/rust/pull/126265/)
• [Improve coverage instrumentation for functions containing nested items.](https://github.com/rust-lang/rust/pull/127199/)
• + 10 more

📦 Libraries

• [Split core's `PanicInfo` and std's `PanicInfo`.](https://github.com/rust-lang/rust/pull/115974/) (see compatibility note below)
• [Generalize `{Rc,Arc}::make_mut()` to unsized types.](https://github.com/rust-lang/rust/pull/116113/)
• [Replace sort implementations with stable `driftsort` and unstable `ipnsort`.](https://github.com/rust-lang/rust/pull/124032/) All `slice::sort*` and `slice::select_nth*` methods are expected to see significant performance improvements. See the [research project](https://github.com/Voultapher/sort-research-rs) for more details.
• [Document behavior of `create_dir_all` with respect to empty paths.](https://github.com/rust-lang/rust/pull/125112/)
• [Fix interleaved output in the default panic hook when multiple threads panic simultaneously.](https://github.com/rust-lang/rust/pull/127397/)
• Fix `Command`'s batch files argument escaping not working when file name has trailing whitespace or periods (CVE-2024-43402).
• <a id="1.81.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`core::error`](https://doc.rust-lang.org/stable/core/error/index.html)
• [`hint::assert_unchecked`](https://doc.rust-lang.org/stable/core/hint/fn.assert_unchecked.html)
• [`fs::exists`](https://doc.rust-lang.org/stable/std/fs/fn.exists.html)
• [`AtomicBool::fetch_not`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicBool.html#method.fetch_not)
• [`Duration::abs_diff`](https://doc.rust-lang.org/stable/core/time/struct.Duration.html#method.abs_diff)
• [`IoSlice::advance`](https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance)
• [`IoSlice::advance_slices`](https://doc.rust-lang.org/stable/std/io/struct.IoSlice.html#method.advance_slices)
• [`IoSliceMut::advance`](https://doc.rust-lang.org/stable/std/io/struct.IoSliceMut.html#method.advance)
• + 10 more

📦 Cargo

• [Generated `.cargo_vcs_info.json` is always included, even when `--allow-dirty` is passed.](https://github.com/rust-lang/cargo/pull/13960/)
• [Disallow `package.license-file` and `package.readme` pointing to non-existent files during packaging.](https://github.com/rust-lang/cargo/pull/13921/)
• [Disallow passing `--release`/`--debug` flag along with the `--profile` flag.](https://github.com/rust-lang/cargo/pull/13971/)
• [Remove `lib.plugin` key support in `Cargo.toml`. Rust plugin support has been deprecated for four years and was removed in 1.75.0.](https://github.com/rust-lang/cargo/pull/13902/)
• <a id="1.81.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• Usage of the `wasm32-wasi` target will now issue a compiler warning and request users switch to the `wasm32-wasip1` target instead. Both targets are the same, `wasm32-wasi` is only being renamed, and this [change to the WASI target](https://blog.rust-lang.org/2024/04/09/updates-to-rusts-wasi-targets.html) is being done to enable removing `wasm32-wasi` in January 2025.
• We have renamed `std::panic::PanicInfo` to `std::panic::PanicHookInfo`. The old name will continue to work as an alias, but will result in a deprecation warning starting in Rust 1.82.0.
• `core::panic::PanicInfo` will remain unchanged, however, as this is now a *different type*.
• The new sort implementations may panic if a type's implementation of [`Ord`](https://doc.rust-lang.org/std/cmp/trait.Ord.html) (or the given comparison function) does not implement a [total order](https://en.wikipedia.org/wiki/Total_order) as the trait requires. `Ord`'s supertraits (`PartialOrd`, `Eq`, and `PartialEq`) must also be consistent. The previous implementations would not "notice" any problem, but the new implementations have a good chance of detecting inconsistencies, throwing a panic rather than returning knowingly unsorted data.
• [In very rare cases, a change in the internal evaluation order of the trait solver may result in new fatal overflow errors.](https://github.com/rust-lang/rust/pull/126128)
• <a id="1.81.0-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.
• [Add a Rust-for-Linux `auto` CI job to check kernel builds.](https://github.com/rust-lang/rust/pull/125209/)

📋 Changes

• [Fix miscompilation in the jump threading MIR optimization when comparing floats](https://github.com/rust-lang/rust/pull/128271)
• [Revert changes to the `dead_code` lint from 1.80.0](https://github.com/rust-lang/rust/pull/128618)

📦 Language

• [Document maximum allocation size](https://github.com/rust-lang/rust/pull/116675/)
• [Allow zero-byte offsets and ZST read/writes on arbitrary pointers](https://github.com/rust-lang/rust/pull/117329/)
• [Support C23's variadics without a named parameter](https://github.com/rust-lang/rust/pull/124048/)
• [Stabilize `exclusive_range_pattern` feature](https://github.com/rust-lang/rust/pull/124459/)
• [Guarantee layout and ABI of `Result` in some scenarios](https://github.com/rust-lang/rust/pull/124870)
• <a id="1.80-Compiler"></a>

📦 Compiler

• [Update cc crate to v1.0.97 allowing additional spectre mitigations on MSVC targets](https://github.com/rust-lang/rust/pull/124892/)
• [Allow field reordering on types marked `repr(packed(1))`](https://github.com/rust-lang/rust/pull/125360/)
• [Add a lint against never type fallback affecting unsafe code](https://github.com/rust-lang/rust/pull/123939/)
• [Disallow cast with trailing braced macro in let-else](https://github.com/rust-lang/rust/pull/125049/)
• [Expand `for_loops_over_fallibles` lint to lint on fallibles behind references.](https://github.com/rust-lang/rust/pull/125156/)
• [self-contained linker: retry linking without `-fuse-ld=lld` on CCs that don't support it](https://github.com/rust-lang/rust/pull/125417/)
• [Do not parse CVarArgs (`...`) as a type in trait bounds](https://github.com/rust-lang/rust/pull/125863/)
• Improvements to LLDB formatting [\#124458](https://github.com/rust-lang/rust/pull/124458) [\#124500](https://github.com/rust-lang/rust/pull/124500)
• + 4 more

📦 Libraries

• [Add `size_of` and `size_of_val` and `align_of` and `align_of_val` to the prelude](https://github.com/rust-lang/rust/pull/123168/)
• [Abort a process when FD ownership is violated](https://github.com/rust-lang/rust/pull/124210/)
• [io::Write::write\_fmt: panic if the formatter fails when the stream does not fail](https://github.com/rust-lang/rust/pull/125012/)
• [Panic if `PathBuf::set_extension` would add a path separator](https://github.com/rust-lang/rust/pull/125070/)
• [Add assert\_unsafe\_precondition to unchecked\_{add,sub,neg,mul,shl,shr} methods](https://github.com/rust-lang/rust/pull/121571/)
• [Update `c_char` on AIX to use the correct type](https://github.com/rust-lang/rust/pull/122986/)
• [`offset_of!` no longer returns a temporary](https://github.com/rust-lang/rust/pull/124484/)
• [Handle sigma in `str.to_lowercase` correctly](https://github.com/rust-lang/rust/pull/124773/)
• + 2 more

📦 Stabilized APIs

• [`impl Default for Rc<CStr>`](https://doc.rust-lang.org/beta/alloc/rc/struct.Rc.html#impl-Default-for-Rc%3CCStr%3E)
• [`impl Default for Rc<str>`](https://doc.rust-lang.org/beta/alloc/rc/struct.Rc.html#impl-Default-for-Rc%3Cstr%3E)
• [`impl Default for Rc<[T]>`](https://doc.rust-lang.org/beta/alloc/rc/struct.Rc.html#impl-Default-for-Rc%3C%5BT%5D%3E)
• [`impl Default for Arc<str>`](https://doc.rust-lang.org/beta/alloc/sync/struct.Arc.html#impl-Default-for-Arc%3Cstr%3E)
• [`impl Default for Arc<CStr>`](https://doc.rust-lang.org/beta/alloc/sync/struct.Arc.html#impl-Default-for-Arc%3CCStr%3E)
• [`impl Default for Arc<[T]>`](https://doc.rust-lang.org/beta/alloc/sync/struct.Arc.html#impl-Default-for-Arc%3C%5BT%5D%3E)
• [`impl IntoIterator for Box<[T]>`](https://doc.rust-lang.org/beta/alloc/boxed/struct.Box.html#impl-IntoIterator-for-Box%3C%5BI%5D,+A%3E)
• [`impl FromIterator<String> for Box<str>`](https://doc.rust-lang.org/beta/alloc/boxed/struct.Box.html#impl-FromIterator%3CString%3E-for-Box%3Cstr%3E)
• + 54 more

📦 Cargo

• [Stabilize `-Zcheck-cfg` as always enabled](https://github.com/rust-lang/cargo/pull/13571/)
• [Warn, rather than fail publish, if a target is excluded](https://github.com/rust-lang/cargo/pull/13713/)
• [Add special `check-cfg` lint config for the `unexpected_cfgs` lint](https://github.com/rust-lang/cargo/pull/13913/)
• [Stabilize `cargo update --precise <yanked>`](https://github.com/rust-lang/cargo/pull/13974/)
• [Don't change file permissions on `Cargo.toml` when using `cargo add`](https://github.com/rust-lang/cargo/pull/13898/)
• [Support using `cargo fix` on IPv6-only networks](https://github.com/rust-lang/cargo/pull/13907/)
• <a id="1.80-Rustdoc"></a>

📝 Rustdoc

• [Allow searching for references](https://github.com/rust-lang/rust/pull/124148/)
• [Stabilize `custom_code_classes_in_docs` feature](https://github.com/rust-lang/rust/pull/124577/)
• [fix: In cross-crate scenarios show enum variants on type aliases of enums](https://github.com/rust-lang/rust/pull/125300/)
• <a id="1.80-Compatibility-Notes"></a>

📦 Compatibility Notes

• [rustfmt estimates line lengths differently when using non-ascii characters](https://github.com/rust-lang/rustfmt/issues/6203)
• [Type aliases are now handled correctly in orphan check](https://github.com/rust-lang/rust/pull/117164/)
• [Allow instructing rustdoc to read from stdin via `-`](https://github.com/rust-lang/rust/pull/124611/)
• [`std::env::{set_var, remove_var}` can no longer be converted to safe function pointers and no longer implement the `Fn` family of traits](https://github.com/rust-lang/rust/pull/124636)
• [Warn (or error) when `Self` constructor from outer item is referenced in inner nested item](https://github.com/rust-lang/rust/pull/124187/)
• [Turn `indirect_structural_match` and `pointer_structural_match` lints into hard errors](https://github.com/rust-lang/rust/pull/124661/)
• [Make `where_clause_object_safety` lint a regular object safety violation](https://github.com/rust-lang/rust/pull/125380/)
• [Turn `proc_macro_back_compat` lint into a hard error.](https://github.com/rust-lang/rust/pull/125596/)
• + 4 more

📋 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.
• Misc improvements to size of generated html by rustdoc e.g. [\#124738](https://github.com/rust-lang/rust/pull/124738/) and [\#123734](https://github.com/rust-lang/rust/pull/123734/)
• [MSVC targets no longer depend on libc](https://github.com/rust-lang/rust/pull/124050/)

📦 Language

• [Stabilize inline `const {}` expressions.](https://github.com/rust-lang/rust/pull/104087/)
• [Prevent opaque types being instantiated twice with different regions within the same function.](https://github.com/rust-lang/rust/pull/116935/)
• [Stabilize WebAssembly target features that are in phase 4 and 5.](https://github.com/rust-lang/rust/pull/117457/)
• [Add the `redundant_lifetimes` lint to detect lifetimes which are semantically redundant.](https://github.com/rust-lang/rust/pull/118391/)
• [Stabilize the `unnameable_types` lint for public types that can't be named.](https://github.com/rust-lang/rust/pull/120144/)
• [Enable debuginfo in macros, and stabilize `-C collapse-macro-debuginfo` and `#[collapse_debuginfo]`.](https://github.com/rust-lang/rust/pull/120845/)
• [Propagate temporary lifetime extension into `if` and `match` expressions.](https://github.com/rust-lang/rust/pull/121346/)
• [Restrict promotion of `const fn` calls.](https://github.com/rust-lang/rust/pull/121557/)
• + 7 more

📦 Compiler

• [Define `-C strip` to only affect binaries, not artifacts like `.pdb`.](https://github.com/rust-lang/rust/pull/115120/)
• [Stabilize `-Crelro-level` for controlling runtime link hardening.](https://github.com/rust-lang/rust/pull/121694/)
• [Stabilize checking of `cfg` names and values at compile-time with `--check-cfg`.](https://github.com/rust-lang/rust/pull/123501/) *Note that this only stabilizes the compiler part, the Cargo part is still unstable in this release.*
• [Add `aarch64-apple-visionos` and `aarch64-apple-visionos-sim` tier 3 targets.](https://github.com/rust-lang/rust/pull/121419/)
• [Add `riscv32ima-unknown-none-elf` tier 3 target.](https://github.com/rust-lang/rust/pull/122696/)
• [Promote several Windows targets to tier 2](https://github.com/rust-lang/rust/pull/121712): `aarch64-pc-windows-gnullvm`, `i686-pc-windows-gnullvm`, and `x86_64-pc-windows-gnullvm`.
• Refer to Rust's [platform support page](https://doc.rust-lang.org/rustc/platform-support.html) for more information on Rust's tiered platform support.
• <a id="1.79.0-Libraries"></a>

📦 Libraries

• [Implement `FromIterator` for `(impl Default + Extend, impl Default + Extend)`.](https://github.com/rust-lang/rust/pull/107462/)
• [Implement `{Div,Rem}Assign<NonZero<X>>` on `X`.](https://github.com/rust-lang/rust/pull/121952/)
• [Document overrides of `clone_from()` in core/std.](https://github.com/rust-lang/rust/pull/122201/)
• [Link MSVC default lib in core.](https://github.com/rust-lang/rust/pull/122268/)
• [Caution against using `transmute` between pointers and integers.](https://github.com/rust-lang/rust/pull/122379/)
• [Enable frame pointers for the standard library.](https://github.com/rust-lang/rust/pull/122646/)
• <a id="1.79.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`{integer}::unchecked_add`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_add)
• [`{integer}::unchecked_mul`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_mul)
• [`{integer}::unchecked_sub`](https://doc.rust-lang.org/stable/core/primitive.i32.html#method.unchecked_sub)
• [`<[T]>::split_at_unchecked`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.split_at_unchecked)
• [`<[T]>::split_at_mut_unchecked`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.split_at_mut_unchecked)
• [`<[u8]>::utf8_chunks`](https://doc.rust-lang.org/stable/core/primitive.slice.html#method.utf8_chunks)
• [`str::Utf8Chunks`](https://doc.rust-lang.org/stable/core/str/struct.Utf8Chunks.html)
• [`str::Utf8Chunk`](https://doc.rust-lang.org/stable/core/str/struct.Utf8Chunk.html)
• + 27 more

📦 Cargo

• [Prevent dashes in `lib.name`, always normalizing to `_`.](https://github.com/rust-lang/cargo/pull/12783/)
• [Stabilize MSRV-aware version requirement selection in `cargo add`.](https://github.com/rust-lang/cargo/pull/13608/)
• [Switch to using `gitoxide` by default for listing files.](https://github.com/rust-lang/cargo/pull/13696/)
• <a id="1.79.0-Rustdoc"></a>

📝 Rustdoc

• [Always display stability version even if it's the same as the containing item.](https://github.com/rust-lang/rust/pull/118441/)
• [Show a single search result for items with multiple paths.](https://github.com/rust-lang/rust/pull/119912/)
• [Support typing `/` in docs to begin a search.](https://github.com/rust-lang/rust/pull/123355/)
• <a id="1.79.0-Misc"></a>

📦 Misc

• <a id="1.79.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Update the minimum external LLVM to 17.](https://github.com/rust-lang/rust/pull/122649/)
• [`RustcEncodable` and `RustcDecodable` are soft-destabilized, to be removed from the prelude in next edition.](https://github.com/rust-lang/rust/pull/116016/)
• [The `wasm_c_abi` future-incompatibility lint will warn about use of the non-spec-compliant C ABI.](https://github.com/rust-lang/rust/pull/117918/) Use `wasm-bindgen v0.2.88` to generate forward-compatible bindings.
• [Check return types of function types for well-formedness](https://github.com/rust-lang/rust/pull/115538)

📦 Language

• [Stabilize `#[cfg(target_abi = ...)]`](https://github.com/rust-lang/rust/pull/119590/)
• [Stabilize the `#[diagnostic]` namespace and `#[diagnostic::on_unimplemented]` attribute](https://github.com/rust-lang/rust/pull/119888/)
• [Make async-fn-in-trait implementable with concrete signatures](https://github.com/rust-lang/rust/pull/120103/)
• [Make matching on NaN a hard error, and remove the rest of `illegal_floating_point_literal_pattern`](https://github.com/rust-lang/rust/pull/116284/)
• [static mut: allow mutable reference to arbitrary types, not just slices and arrays](https://github.com/rust-lang/rust/pull/117614/)
• [Extend `invalid_reference_casting` to include references casting to bigger memory layout](https://github.com/rust-lang/rust/pull/118983/)
• [Add `non_contiguous_range_endpoints` lint for singleton gaps after exclusive ranges](https://github.com/rust-lang/rust/pull/118879/)
• [Add `wasm_c_abi` lint for use of older wasm-bindgen versions](https://github.com/rust-lang/rust/pull/117918/) This lint currently only works when using Cargo.
• + 7 more

📦 Compiler

• [Made `INVALID_DOC_ATTRIBUTES` lint deny by default](https://github.com/rust-lang/rust/pull/111505/)
• [Increase accuracy of redundant `use` checking](https://github.com/rust-lang/rust/pull/117772/)
• [Suggest moving definition if non-found macro\_rules\! is defined later](https://github.com/rust-lang/rust/pull/121130/)
• [Lower transmutes from int to pointer type as gep on null](https://github.com/rust-lang/rust/pull/121282/)
• Target changes:
• [Windows tier 1 targets now require at least Windows 10](https://github.com/rust-lang/rust/pull/115141/)
• [Enable CMPXCHG16B, SSE3, SAHF/LAHF and 128-bit Atomics in tier 1 Windows](https://github.com/rust-lang/rust/pull/120820/)
• [Add `wasm32-wasip1` tier 2 (without host tools) target](https://github.com/rust-lang/rust/pull/120468/)
• + 7 more

📦 Libraries

• [Bump Unicode to version 15.1.0, regenerate tables](https://github.com/rust-lang/rust/pull/120777/)
• [Make align\_offset, align\_to well-behaved in all cases](https://github.com/rust-lang/rust/pull/121201/)
• [PartialEq, PartialOrd: document expectations for transitive chains](https://github.com/rust-lang/rust/pull/115386/)
• [Optimize away poison guards when std is built with panic=abort](https://github.com/rust-lang/rust/pull/100603/)
• [Replace pthread `RwLock` with custom implementation](https://github.com/rust-lang/rust/pull/110211/)
• [Implement unwind safety for Condvar on all platforms](https://github.com/rust-lang/rust/pull/121768/)
• [Add ASCII fast-path for `char::is_grapheme_extended`](https://github.com/rust-lang/rust/pull/121138/)
• <a id="1.78.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`impl Read for &Stdin`](https://doc.rust-lang.org/stable/std/io/struct.Stdin.html#impl-Read-for-%26Stdin)
• [Accept non `'static` lifetimes for several `std::error::Error` related implementations](https://github.com/rust-lang/rust/pull/113833/)
• [Make `impl<Fd: AsFd>` impl take `?Sized`](https://github.com/rust-lang/rust/pull/114655/)
• [`impl From<TryReserveError> for io::Error`](https://doc.rust-lang.org/stable/std/io/struct.Error.html#impl-From%3CTryReserveError%3E-for-Error)
• These APIs are now stable in const contexts:
• [`Barrier::new()`](https://doc.rust-lang.org/stable/std/sync/struct.Barrier.html#method.new)
• <a id="1.78.0-Cargo"></a>

📦 Cargo

• [Stabilize lockfile v4](https://github.com/rust-lang/cargo/pull/12852/)
• [Respect `rust-version` when generating lockfile](https://github.com/rust-lang/cargo/pull/12861/)
• [Control `--charset` via auto-detecting config value](https://github.com/rust-lang/cargo/pull/13337/)
• [Support `target.<triple>.rustdocflags` officially](https://github.com/rust-lang/cargo/pull/13197/)
• [Stabilize global cache data tracking](https://github.com/rust-lang/cargo/pull/13492/)
• <a id="1.78.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Many unsafe precondition checks now run for user code with debug assertions enabled](https://github.com/rust-lang/rust/pull/120594/) This change helps users catch undefined behavior in their code, though the details of how much is checked are generally not stable.
• [riscv only supports split\_debuginfo=off for now](https://github.com/rust-lang/rust/pull/120518/)
• [Consistently check bounds on hidden types of `impl Trait`](https://github.com/rust-lang/rust/pull/121679)
• [Change equality of higher ranked types to not rely on subtyping](https://github.com/rust-lang/rust/pull/118247)
• [When called, additionally check bounds on normalized function return type](https://github.com/rust-lang/rust/pull/118882)
• [Expand coverage for `arithmetic_overflow` lint](https://github.com/rust-lang/rust/pull/119432/)
• [Fix detection of potential interior mutability in `const` initializers](https://github.com/rust-lang/rust/issues/121250) This code was accidentally accepted. The fix can break generic code that borrows a value of unknown type, as there is currently no way to declare "this type has no interior mutability". In the future, stabilizing the [`Freeze` trait](https://github.com/rust-lang/rust/issues/121675) will allow proper support for such code.
• <a id="1.78.0-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.
• [Update to LLVM 18](https://github.com/rust-lang/rust/pull/120055/)
• [Build `rustc` with 1CGU on `x86_64-pc-windows-msvc`](https://github.com/rust-lang/rust/pull/112267/)
• [Build `rustc` with 1CGU on `x86_64-apple-darwin`](https://github.com/rust-lang/rust/pull/112268/)
• [Introduce `run-make` V2 infrastructure, a `run_make_support` library and port over 2 tests as example](https://github.com/rust-lang/rust/pull/113026/)
• [Windows: Implement condvar, mutex and rwlock using futex](https://github.com/rust-lang/rust/pull/121956/)

📋 Changes

• [CVE-2024-24576: fix escaping of Windows batch file arguments in `std::process::Command`](https://blog.rust-lang.org/2024/04/09/cve-2024-24576.html)

📋 Changes

• [Revert stripping debuginfo by default for Windows](https://github.com/rust-lang/cargo/pull/13654) This fixes a regression in 1.77 by reverting to the previous default. Platforms other than Windows are not affected.
• Internal: [Fix heading anchor rendering in doc pages](https://github.com/rust-lang/rust/pull/122693)

📦 Language

• [Reveal opaque types within the defining body for exhaustiveness checking.](https://github.com/rust-lang/rust/pull/116821/)
• [Stabilize C-string literals.](https://github.com/rust-lang/rust/pull/117472/)
• [Stabilize THIR unsafeck.](https://github.com/rust-lang/rust/pull/117673/)
• [Add lint `static_mut_refs` to warn on references to mutable statics.](https://github.com/rust-lang/rust/pull/117556/)
• [Support async recursive calls (as long as they have indirection).](https://github.com/rust-lang/rust/pull/117703/)
• [Undeprecate lint `unstable_features` and make use of it in the compiler.](https://github.com/rust-lang/rust/pull/118639/)
• [Make inductive cycles in coherence ambiguous always.](https://github.com/rust-lang/rust/pull/118649/)
• [Get rid of type-driven traversal in const-eval interning](https://github.com/rust-lang/rust/pull/119044/), only as a [future compatibility lint](https://github.com/rust-lang/rust/pull/122204) for now.
• + 2 more

📦 Compiler

• [Include lint `soft_unstable` in future breakage reports.](https://github.com/rust-lang/rust/pull/116274/)
• [Make `i128` and `u128` 16-byte aligned on x86-based targets.](https://github.com/rust-lang/rust/pull/116672/)
• [Use `--verbose` in diagnostic output.](https://github.com/rust-lang/rust/pull/119129/)
• [Improve spacing between printed tokens.](https://github.com/rust-lang/rust/pull/120227/)
• [Merge the `unused_tuple_struct_fields` lint into `dead_code`.](https://github.com/rust-lang/rust/pull/118297/)
• [Error on incorrect implied bounds in well-formedness check](https://github.com/rust-lang/rust/pull/118553/), with a temporary exception for Bevy.
• [Fix coverage instrumentation/reports for non-ASCII source code.](https://github.com/rust-lang/rust/pull/119033/)
• [Fix `fn`/`const` items implied bounds and well-formedness check.](https://github.com/rust-lang/rust/pull/120019/)
• + 8 more

📦 Libraries

• [Implement `From<&[T; N]>` for `Cow<[T]>`.](https://github.com/rust-lang/rust/pull/113489/)
• [Remove special-case handling of `vec.split_off(0)`.](https://github.com/rust-lang/rust/pull/119917/)
• <a id="1.77.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`array::each_ref`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_ref)
• [`array::each_mut`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_mut)
• [`core::net`](https://doc.rust-lang.org/stable/core/net/index.html)
• [`f32::round_ties_even`](https://doc.rust-lang.org/stable/std/primitive.f32.html#method.round_ties_even)
• [`f64::round_ties_even`](https://doc.rust-lang.org/stable/std/primitive.f64.html#method.round_ties_even)
• [`mem::offset_of!`](https://doc.rust-lang.org/stable/std/mem/macro.offset_of.html)
• [`slice::first_chunk`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first_chunk)
• [`slice::first_chunk_mut`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.first_chunk_mut)
• + 13 more

📦 Cargo

• [Extend the build directive syntax with `cargo::`.](https://github.com/rust-lang/cargo/pull/12201/)
• [Stabilize metadata `id` format as `PackageIDSpec`.](https://github.com/rust-lang/cargo/pull/12914/)
• [Pull out `cargo-util-schemas` as a crate.](https://github.com/rust-lang/cargo/pull/13178/)
• [Strip all debuginfo when debuginfo is not requested.](https://github.com/rust-lang/cargo/pull/13257/)
• [Inherit jobserver from env for all kinds of runners.](https://github.com/rust-lang/cargo/pull/12776/)
• [Deprecate rustc plugin support in cargo.](https://github.com/rust-lang/cargo/pull/13248/)
• <a id="1.77.0-Rustdoc"></a>

📝 Rustdoc

• [Allows links in markdown headings.](https://github.com/rust-lang/rust/pull/117662/)
• [Search for tuples and unit by type with `()`.](https://github.com/rust-lang/rust/pull/118194/)
• [Clean up the source sidebar's hide button.](https://github.com/rust-lang/rust/pull/119066/)
• [Prevent JS injection from `localStorage`.](https://github.com/rust-lang/rust/pull/120250/)
• <a id="1.77.0-Misc"></a>

📦 Misc

• [Recommend version-sorting for all sorting in style guide.](https://github.com/rust-lang/rust/pull/115046/)
• <a id="1.77.0-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.
• [Add more weirdness to `weird-exprs.rs`.](https://github.com/rust-lang/rust/pull/119028/)

📦 Language

• [Document Rust ABI compatibility between various types](https://github.com/rust-lang/rust/pull/115476/)
• [Also: guarantee that char and u32 are ABI-compatible](https://github.com/rust-lang/rust/pull/118032/)
• [Add lint `ambiguous_wide_pointer_comparisons` that supersedes `clippy::vtable_address_comparisons`](https://github.com/rust-lang/rust/pull/117758)
• <a id="1.76.0-Compiler"></a>

📦 Compiler

• [Lint pinned `#[must_use]` pointers (in particular, `Box<T>` where `T` is `#[must_use]`) in `unused_must_use`.](https://github.com/rust-lang/rust/pull/118054/)
• [Soundness fix: fix computing the offset of an unsized field in a packed struct](https://github.com/rust-lang/rust/pull/118540/)
• [Soundness fix: fix dynamic size/align computation logic for packed types with dyn Trait tail](https://github.com/rust-lang/rust/pull/118538/)
• [Add `$message_type` field to distinguish json diagnostic outputs](https://github.com/rust-lang/rust/pull/115691/)
• [Enable Rust to use the EHCont security feature of Windows](https://github.com/rust-lang/rust/pull/118013/)
• [Add tier 3 {x86\_64,i686}-win7-windows-msvc targets](https://github.com/rust-lang/rust/pull/118150/)
• [Add tier 3 aarch64-apple-watchos target](https://github.com/rust-lang/rust/pull/119074/)
• [Add tier 3 arm64e-apple-ios & arm64e-apple-darwin targets](https://github.com/rust-lang/rust/pull/115526/)
• + 2 more

📦 Libraries

• [Add a column number to `dbg!()`](https://github.com/rust-lang/rust/pull/114962/)
• [Add `std::hash::{DefaultHasher, RandomState}` exports](https://github.com/rust-lang/rust/pull/115694/)
• [Fix rounding issue with exponents in fmt](https://github.com/rust-lang/rust/pull/116301/)
• [Add T: ?Sized to `RwLockReadGuard` and `RwLockWriteGuard`'s Debug impls.](https://github.com/rust-lang/rust/pull/117138/)
• [Windows: Allow `File::create` to work on hidden files](https://github.com/rust-lang/rust/pull/116438/)
• <a id="1.76.0-Stabilized-APIs"></a>

📦 Stabilized APIs

• [`Arc::unwrap_or_clone`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.unwrap_or_clone)
• [`Rc::unwrap_or_clone`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.unwrap_or_clone)
• [`Result::inspect`](https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.inspect)
• [`Result::inspect_err`](https://doc.rust-lang.org/stable/std/result/enum.Result.html#method.inspect_err)
• [`Option::inspect`](https://doc.rust-lang.org/stable/std/option/enum.Option.html#method.inspect)
• [`type_name_of_val`](https://doc.rust-lang.org/stable/std/any/fn.type_name_of_val.html)
• [`std::hash::{DefaultHasher, RandomState}`](https://doc.rust-lang.org/stable/std/hash/index.html#structs) These were previously available only through `std::collections::hash_map`.
• [`ptr::{from_ref, from_mut}`](https://doc.rust-lang.org/stable/std/ptr/fn.from_ref.html)
• + 2 more

📦 Cargo

• See [Cargo release notes](https://github.com/rust-lang/cargo/blob/master/CHANGELOG.md#cargo-176-2024-02-08).
• <a id="1.76.0-Rustdoc"></a>

📝 Rustdoc

• [Don't merge cfg and doc(cfg) attributes for re-exports](https://github.com/rust-lang/rust/pull/113091/)
• [rustdoc: allow resizing the sidebar / hiding the top bar](https://github.com/rust-lang/rust/pull/115660/)
• [rustdoc-search: add support for traits and associated types](https://github.com/rust-lang/rust/pull/116085/)
• [rustdoc: Add highlighting for comments in items declaration](https://github.com/rust-lang/rust/pull/117869/)
• <a id="1.76.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [Add allow-by-default lint for unit bindings](https://github.com/rust-lang/rust/pull/112380/) This is expected to be upgraded to a warning by default in a future Rust release. Some macros emit bindings with type `()` with user-provided spans, which means that this lint will warn for user code.
• [Remove x86\_64-sun-solaris target.](https://github.com/rust-lang/rust/pull/118091/)
• [Remove asmjs-unknown-emscripten target](https://github.com/rust-lang/rust/pull/117338/)
• [Report errors in jobserver inherited through environment variables](https://github.com/rust-lang/rust/pull/113730/) This [may warn](https://github.com/rust-lang/rust/issues/120515) on benign problems too.
• [Update the minimum external LLVM to 16.](https://github.com/rust-lang/rust/pull/117947/)
• [Improve `print_tts`](https://github.com/rust-lang/rust/pull/114571/) This change can break some naive manual parsing of token trees in proc macro code which expect a particular structure after `.to_string()`, rather than just arbitrary Rust code.
• [Make `IMPLIED_BOUNDS_ENTAILMENT` into a hard error from a lint](https://github.com/rust-lang/rust/pull/117984/)
• [Vec's allocation behavior was changed when collecting some iterators](https://github.com/rust-lang/rust/pull/110353) Allocation behavior is currently not specified, nevertheless changes can be surprising. See [`impl FromIterator for Vec`](https://doc.rust-lang.org/nightly/std/vec/struct.Vec.html#impl-FromIterator%3CT%3E-for-Vec%3CT%3E) for more details.
• + 1 more

📦 Language

• [Stabilize `async fn` and return-position `impl Trait` in traits.](https://github.com/rust-lang/rust/pull/115822/)
• [Allow function pointer signatures containing `&mut T` in `const` contexts.](https://github.com/rust-lang/rust/pull/116015/)
• [Match `usize`/`isize` exhaustively with half-open ranges.](https://github.com/rust-lang/rust/pull/116692/)
• [Guarantee that `char` has the same size and alignment as `u32`.](https://github.com/rust-lang/rust/pull/116894/)
• [Document that the null pointer has the 0 address.](https://github.com/rust-lang/rust/pull/116988/)
• [Allow partially moved values in `match`.](https://github.com/rust-lang/rust/pull/103208/)
• [Add notes about non-compliant FP behavior on 32bit x86 targets.](https://github.com/rust-lang/rust/pull/113053/)
• [Stabilize ratified RISC-V target features.](https://github.com/rust-lang/rust/pull/116485/)
• + 1 more

📦 Compiler

• [Rework negative coherence to properly consider impls that only partly overlap.](https://github.com/rust-lang/rust/pull/112875/)
• [Bump `COINDUCTIVE_OVERLAP_IN_COHERENCE` to deny, and warn in dependencies.](https://github.com/rust-lang/rust/pull/116493/)
• [Consider alias bounds when computing liveness in NLL.](https://github.com/rust-lang/rust/pull/116733/)
• [Add the V (vector) extension to the `riscv64-linux-android` target spec.](https://github.com/rust-lang/rust/pull/116618/)
• [Automatically enable cross-crate inlining for small functions](https://github.com/rust-lang/rust/pull/116505)
• Add several new tier 3 targets:
• [`csky-unknown-linux-gnuabiv2hf`](https://github.com/rust-lang/rust/pull/117049/)
• [`i586-unknown-netbsd`](https://github.com/rust-lang/rust/pull/117170/)
• + 3 more

📦 Libraries

• [Override `Waker::clone_from` to avoid cloning `Waker`s unnecessarily.](https://github.com/rust-lang/rust/pull/96979/)
• [Implement `BufRead` for `VecDeque<u8>`.](https://github.com/rust-lang/rust/pull/110604/)
• [Implement `FusedIterator` for `DecodeUtf16` when the inner iterator does.](https://github.com/rust-lang/rust/pull/110729/)
• [Implement `Not, Bit{And,Or}{,Assign}` for IP addresses.](https://github.com/rust-lang/rust/pull/113747/)
• [Implement `Default` for `ExitCode`.](https://github.com/rust-lang/rust/pull/114589/)
• [Guarantee representation of None in NPO](https://github.com/rust-lang/rust/pull/115333/)
• [Document when atomic loads are guaranteed read-only.](https://github.com/rust-lang/rust/pull/115577/)
• [Broaden the consequences of recursive TLS initialization.](https://github.com/rust-lang/rust/pull/116172/)
• + 4 more

📦 Stabilized APIs

• [`Atomic*::from_ptr`](https://doc.rust-lang.org/stable/core/sync/atomic/struct.AtomicUsize.html#method.from_ptr)
• [`FileTimes`](https://doc.rust-lang.org/stable/std/fs/struct.FileTimes.html)
• [`FileTimesExt`](https://doc.rust-lang.org/stable/std/os/windows/fs/trait.FileTimesExt.html)
• [`File::set_modified`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_modified)
• [`File::set_times`](https://doc.rust-lang.org/stable/std/fs/struct.File.html#method.set_times)
• [`IpAddr::to_canonical`](https://doc.rust-lang.org/stable/core/net/enum.IpAddr.html#method.to_canonical)
• [`Ipv6Addr::to_canonical`](https://doc.rust-lang.org/stable/core/net/struct.Ipv6Addr.html#method.to_canonical)
• [`Option::as_slice`](https://doc.rust-lang.org/stable/core/option/enum.Option.html#method.as_slice)
• + 15 more

📦 Cargo

• [Add new packages to `[workspace.members]` automatically.](https://github.com/rust-lang/cargo/pull/12779/)
• [Allow version-less `Cargo.toml` manifests.](https://github.com/rust-lang/cargo/pull/12786/)
• [Make browser links out of HTML file paths.](https://github.com/rust-lang/cargo/pull/12889)
• <a id="1.75.0-Rustdoc"></a>

📝 Rustdoc

• [Accept less invalid Rust in rustdoc.](https://github.com/rust-lang/rust/pull/117450/)
• [Document lack of object safety on affected traits.](https://github.com/rust-lang/rust/pull/113241/)
• [Hide `#[repr(transparent)]` if it isn't part of the public ABI.](https://github.com/rust-lang/rust/pull/115439/)
• [Show enum discriminant if it is a C-like variant.](https://github.com/rust-lang/rust/pull/116142/)
• <a id="1.75.0-Compatibility-Notes"></a>

📦 Compatibility Notes

• [FreeBSD targets now require at least version 12.](https://github.com/rust-lang/rust/pull/114521/)
• [Formally demote tier 2 MIPS targets to tier 3.](https://github.com/rust-lang/rust/pull/115238/)
• [Make misalignment a hard error in `const` contexts.](https://github.com/rust-lang/rust/pull/115524/)
• [Fix detecting references to packed unsized fields.](https://github.com/rust-lang/rust/pull/115583/)
• [Remove support for compiler plugins.](https://github.com/rust-lang/rust/pull/116412/)
• <a id="1.75.0-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.
• [Optimize `librustc_driver.so` with BOLT.](https://github.com/rust-lang/rust/pull/116352/)
• [Enable parallel rustc front end in dev and nightly builds.](https://github.com/rust-lang/rust/pull/117435/)
• [Distribute `rustc-codegen-cranelift` as rustup component on the nightly channel.](https://github.com/rust-lang/rust/pull/81746/)