Draft release notes for 1.94.0 #151650
Description
NOTE: Use the 📝 links to edit those that have a relnotes-tracking-issue,
and they will be updated when we regenerate the notes periodically (manually).
Version 1.94.0 (2026-03-05)
Language
- Impls and impl items inherit
dead_codelint level of the corresponding traits and trait items
📝 - Stabilize additional 29 RISC-V target features including large portions of the RVA22U64 / RVA23U64 profiles
📝 - Add warn-by-default lint for visibility on
const _declarations
📝 - Update to Unicode 17
📝 - Avoid incorrect lifetime errors for closures
📝
Compiler
Platform Support
Refer to Rust's platform support page
for more information on Rust's tiered platform support.
Libraries
- Relax
T: Ordbound for someBinaryHeap<T>methods.
📝
Stabilized APIs
[T]::array_windows
📝LazyCell::getLazyCell::get_mutLazyCell::force_mutLazyLock::getLazyLock::get_mutLazyLock::force_mut
📝impl TryFrom<char> for usize
📝std::iter::Peekable::next_if_mapstd::iter::Peekable::next_if_map_mut
📝- x86
avx512fp16intrinsics
This excludes those that depend directly on the unstablef16type. - AArch64 NEON fp16 intrinsics
This excludes those that depend directly on the unstablef16type.
📝 <[T]>::element_offset
📝f32::consts::EULER_GAMMAf64::consts::EULER_GAMMAf32::consts::GOLDEN_RATIOf64::consts::GOLDEN_RATIO
📝
These previously stable APIs are now stable in const contexts:
Cargo
- feat: stabilize
-Zconfig-include - fix(package): Don't verify registry for --list
- feat(index): Stabilize pubtime
- feat(toml): TOML 1.1 parse support
- fix(timing)!: remove
--timings=<FMT>optional format values - feat(test): Make CARGO_BIN_EXE_ available at runtime
Compatibility Notes
- Forbid freely casting lifetime bounds of
dyn-types
📝 - Make closure capturing have consistent and correct behaviour around patterns
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.
📝 - core and std macros are now imported via prelude, not via injected
#[macro_use]
This may raise a new warning (ambiguous_panic_imports) on#![no_std]code glob importing the std crate.
Bothcore::panic!andstd::panic!are then in scope and which is used is ambiguous.
📝 - Don't strip
include!(…)shebang in expression context
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
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
📝 - Introduce a future compatibility warning on codegen attributes on body-free trait methods
These attributes have no effect in this position today.
📝 - On Windows
std::time::SystemTime::checked_sub_durationwill returnNonefor times before the Windows epoch (1/1/1601)
📝 - Lifetime identifiers such as
'aare now NFC normalized.
📝 - Overhaul filename handling for cross-compiler consistency
Any paths emitted by compiler now always respect the relative-ness of the paths and--remap-path-prefixgiven originally.
One side-effect of this change is that paths emitted for local crates in Cargo (path dependencies and workspace members) are no longer absolute but relative when emitted as part of a diagnostic in a downstream crate.
📝
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-snippetsfor error emission
This should preserve mostly the same outputs in rustc error messages.
📝