RUST-1.95.0 release notes and known issues

Summary

Language Stabilize if let guards on match arms irrefutable_let_patterns lint no longer lints on let chains Support importing path-segment keywords with renaming Stabilize inline assembly for PowerPC and PowerPC64 const-eval: be more consistent in the behavior of padding during typed copies Const blocks are no longer evaluated to determine if expressions involving fallible operations can implicitly be constant-promoted. . 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 Compiler Stabilize --remap-path-scope for controlling the scoping of how paths get remapped in the resulting binary Apply patches for CVE-2026-6042 and CVE-2026-40200 to vendored musl Platform Support Promote powerpc64-unknown-linux-musl to Tier 2 with host tools Promote aarch64-apple-tvos to Tier 2 Promote aarch64-apple-tvos-sim to Tier 2 Promote aarch64-apple-watchos to Tier 2 Promote aarch64-apple-watchos-sim to Tier 2 Promote aarch64-apple-visionos to Tier 2 Promote aarch64-apple-visionos-sim to Tier 2 Refer to Rust's platform support page for more information on Rust's tiered platform support. Libraries thread::scope : document how join interacts with TLS destructors Speed up str::contains on aarch64 targets with neon target feature enabled by default Stabilized APIs MaybeUninit<[T; N]>: From<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>]> [MaybeUninit<T>; N]: From<MaybeUninit<[T; N]>> Cell<[T; N]>: AsRef<[Cell<T>; N]> Cell<[T; N]>: AsRef<[Cell<T>]> Cell<[T]>: AsRef<[Cell<T>]> bool: TryFrom<{integer}> AtomicPtr::update AtomicPtr::try_update AtomicBool::update AtomicBool::try_update AtomicIn::update AtomicIn::try_update AtomicUn::update AtomicUn::try_update cfg_select! mod core::range core::range::RangeInclusive core::range::RangeInclusiveIter core::hint::cold_path <*const T>::as_ref_unchecked <*mut T>::as_ref_unchecked <*mut T>::as_mut_unchecked Vec::push_mut Vec::insert_mut VecDeque::push_front_mut VecDeque::push_back_mut VecDeque::insert_mut LinkedList::push_front_mut LinkedList::push_back_mut Layout::dangling_ptr Layout::repeat Layout::repeat_packed Layout::extend_packed These previously stable APIs are now stable in const contexts: fmt::from_fn ControlFlow::is_break ControlFlow::is_continue Rustdoc In search results, rank unstable items lower Add new "hide deprecated items" setting in rustdoc Compatibility Notes Array coercions may now result in less inference constraints than before 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. 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 Check lifetime bounds of types mentioning only type parameters Report more visibility-related ambiguous import errors Deprecate Eq::assert_receiver_is_total_eq and emit future compatibility warnings on manual impls powerpc64: Use the ELF ABI version set in target spec instead of guessing (fixes the ELF ABI used by the OpenBSD target) Matching on a #[non_exhaustive] enum now reads the discriminant, even if the enum has only one variant . This can cause closures to capture values that they previously wouldn't. mut ref and mut ref mut patterns, part of the unstable Match Ergonomics 2024 RFC , were accidentally allowed on stable within struct pattern field shorthand. These patterns are now correctly feature-gated as unstable in this position. Add future-compatibility warning for d

Improvements and security content

• Language Stabilize if let guards on match arms irrefutable_let_patterns lint no longer lints on let chains Support importing path-segment keywords with renaming Stabilize inline assembly for PowerPC and PowerPC64 const-eval: be more consistent in the behavior of padding during typed copies Const blocks are no longer evaluated to determine if expressions involving fallible operations can implicitly be constant-promoted. . 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 Compiler Stabilize --remap-path-scope for controlling the scoping of how paths get remapped in the resulting binary Apply patches for CVE-2026-6042 and CVE-2026-40200 to vendored musl Platform Support Promote powerpc64-unknown-linux-musl to Tier 2 with host tools Promote aarch64-apple-tvos to Tier 2 Promote aarch64-apple-tvos-sim to Tier 2 Promote aarch64-apple-watchos to Tier 2 Promote aarch64-apple-watchos-sim to Tier 2 Promote aarch64-apple-visionos to Tier 2 Promote aarch64-apple-visionos-sim to Tier 2 Refer to Rust's platform support page for more information on Rust's tiered platform support. Libraries thread::scope : document how join interacts with TLS destructors Speed up str::contains on aarch64 targets with neon target feature enabled by default Stabilized APIs MaybeUninit<[T; N]>: From<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsRef<[MaybeUninit<T>]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>; N]> MaybeUninit<[T; N]>: AsMut<[MaybeUninit<T>]> [MaybeUninit<T>; N]: From<MaybeUninit<[T; N]>> Cell<[T; N]>: AsRef<[Cell<T>; N]> Cell<[T; N]>: AsRef<[Cell<T>]> Cell<[T]>: AsRef<[Cell<T>]> bool: TryFrom<{integer}> AtomicPtr::update AtomicPtr::try_update AtomicBool::update AtomicBool::try_update AtomicIn::update AtomicIn::try_update AtomicUn::update AtomicUn::try_update cfg_select! mod core::range core::range::RangeInclusive core::range::RangeInclusiveIter core::hint::cold_path <*const T>::as_ref_unchecked <*mut T>::as_ref_unchecked <*mut T>::as_mut_unchecked Vec::push_mut Vec::insert_mut VecDeque::push_front_mut VecDeque::push_back_mut VecDeque::insert_mut LinkedList::push_front_mut LinkedList::push_back_mut Layout::dangling_ptr Layout::repeat Layout::repeat_packed Layout::extend_packed These previously stable APIs are now stable in const contexts: fmt::from_fn ControlFlow::is_break ControlFlow::is_continue Rustdoc In search results, rank unstable items lower Add new "hide deprecated items" setting in rustdoc Compatibility Notes Array coercions may now result in less inference constraints than before 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. 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 Check lifetime bounds of types mentioning only type parameters Report more visibility-related ambiguous import errors Deprecate Eq::assert_receiver_is_total_eq and emit future compatibility warnings on manual impls powerpc64: Use the ELF ABI version set in target spec instead of guessing (fixes the ELF ABI used by the OpenBSD target) Matching on a #[non_exhaustive] enum now reads the discriminant, even if the enum has only one variant . This can cause closures to capture values that they previously wouldn't. mut ref and mut ref mut patterns, part of the unstable Match Ergonomics 2024 RFC , were accidentally allowed on stable within struct pattern field shorthand. These patterns are now correctly feature-gated as unstable in this position. Add future-compatibility warning for d

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