Language¶

• Allow passing expr metavariable to cfg

• Always coerce never types in tuple expressions

• Avoid incorrect inference guidance of function arguments in rare cases

• Support s390x vector registers in inline assembly

• Allow using constants of type ManuallyDrop as patterns (fixing a regression introduced in 1.94.0)

Compiler¶

• Enable link relaxation feature for LoongArch Linux targets

• Update riscv64gc-unknown-fuchsia baseline to RVA22 + vector

Libraries¶

• Support iterating over ranges of NonZero integers

• refactor ‘valid for read/write’ definition: exclude null; add that as an exception on individual methods instead

• Fix SGX delayed host lookup via ToSocketAddr

Stabilized APIs¶

• assert_matches!

• debug_assert_matches!

• From<T> for AssertUnwindSafe<T>

• From<T> for LazyCell<T, F>

• From<T> for LazyLock<T, F>

• core::range::RangeToInclusive

• core::range::RangeToInclusiveIter

• core::range::RangeFrom

• core::range::RangeFromIter

• core::range::Range

• core::range::RangeIter

Cargo¶

• Allow a dependency to specify both a git repository and an alternate registry. 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.

• Fixed CVE-2026-5222 and CVE-2026-5223.

Rustdoc¶

• Deprecation notes are now rendered like any other documentation. 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

• Separate methods and associated functions in sidebar

Compatibility Notes¶

• Fix layout of #[repr(Int)] enums in some edge cases involving fields of uninhabited zero-sized types

• 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.

• rustc: Stop passing --allow-undefined on wasm targets

• Gate the accidentally stabilized #![reexport_test_harness_main] attribute

• Error on return-position-impl-trait-in-traits whose types are too private

• Report the uninhabited_static lint in dependencies and make it deny-by-default

• Distributed builds now contain non-split debuginfo for windows-gnu 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

• Remove -Csoft-float

• Importing structs with ::{self [as name]}, e.g., struct S {}; use S::{self as Other};, is now no longer permitted because {self} imports require a module parent.

• For export_name, link_name, and link_section attributes, if multiple of the same attribute is present, the first one now takes precedence.

• Update the minimum external LLVM to 21

• On avr targets, C’s double type is 32-bit by default, so change c_double to f32 on avr targets to match. This is a breaking change, but necessary to make c_double match C’s double.

• BTreeMap::append() was optimized, which may now cause panics for types with incorrect Ord impls

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"

• target specs: stricter checks for LLVM ABI values, and correlate that with cfg(target_abi)

Language¶

• Consider Result<T, Uninhabited> and ControlFlow<Uninhabited, T> to be equivalent to T for must use lint

• Add allow-by-default dead_code_pub_in_binary lint for unused pub items in binary crates

• Stabilize the div32, lam-bh, lamcas, ld-seq-sa and scq target features

• Stabilize cfg(target_has_atomic_primitive_alignment)

• Allow trailing self in imports in more cases

Platform Support¶

• nvptx64-nvidia-cuda: drop support for old architectures and old ISAs

Refer to Rust’s platform support page for more information on Rust’s tiered platform support.

Stabilized APIs¶

• Default for RepeatN

• Copy for ffi::FromBytesUntilNulError

• Send for std::fs::File on UEFI

• <{integer}>::isolate_highest_one

• <{integer}>::isolate_lowest_one

• <{integer}>::highest_one

• <{integer}>::lowest_one

• <{integer}>::bit_width

• NonZero<{integer}>::isolate_highest_one

• NonZero<{integer}>::isolate_lowest_one

• NonZero<{integer}>::highest_one

• NonZero<{integer}>::lowest_one

• NonZero<{integer}>::bit_width

These previously stable APIs are now stable in const contexts:

• char::is_control

Cargo¶

• Stabilize build.warnings config. This controls how lint warnings from local packages are treated. Useful for enforcing a warning-free build in CI, replacing -Dwarnings. docs

• Stabilize resolver.lockfile-path config. This allows specifying the path to the lockfile to use when resolving dependencies. Useful when working with read-only source directories. docs

• cargo-clean: Error when --target-dir doesn’t look like a Cargo target directory. This prevents accidental deletion of non-target directories.

• Add -m shorthand for --manifest-path

• Remove curl dependency from crates-io crate

Rustdoc¶

• Stabilize --emit flag

• Stabilize --remap-path-prefix

Compatibility Notes¶

• Emit a future-compatibility warning when relying on f32: From<{float}> to constrain {float}

• Rust will use the v0 symbol mangling scheme by default. This may cause some tools (such as debuggers or profilers, especially with old versions) to fail to demangle symbols emitted by Rust. It may also cause the formatting of text in backtraces to change.

• Prevent deref coercions in pin!, in order to prevent unsoundness. The most likely case where this might impact users is: writing pin!(x) where x has type &mut T will now always correctly produce a value of type Pin<&mut &mut T>, instead of sometimes allowing a coercion that produces a value of type Pin<&mut T>. This coercion was previously incorrectly allowed since Rust 1.88.0.

• Deprecate std::char constants and functions

• Warn on linker output by default

• Remove hidden f64 methods which have been deprecated since 1.0

• report the varargs_without_pattern lint in deps

• Forbid passing generic arguments to module path segments even if the module reexports a generic enum variant

• Error on invalid macho link_section specifier

• The encoding of certain enums have changed. This is not a breaking change, as it only applies to enums without layout guarantees, but is noted here as we’ve seen people impacted from having made assumptions about the layout algorithm.

• Error on #[export_name = "..."] where the name is empty

• Syntactically reject tuple index shorthands in struct patterns

• validate #[link_name = "..."] & #[link(name = "...")] parameters

• On Windows, after calling shutdown on a socket to shut down the write side, attempting to write to the socket will now produce a BrokenPipe error rather than Other. Map WSAESHUTDOWN to io::ErrorKind::BrokenPipe