Draft release notes for 1.94.0

[Mark-Simulacrum]

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_code lint 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

• Enable outline-atomics by default on more AArch64 platforms
  📝

Platform Support

• Add riscv64im-unknown-none-elf as a tier 3 target
  📝

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

Libraries

• Relax T: Ord bound for some BinaryHeap<T> methods.
  📝

Stabilized APIs

• [T]::array_windows
  📝
• LazyCell::get
• LazyCell::get_mut
• LazyCell::force_mut
• LazyLock::get
• LazyLock::get_mut
• LazyLock::force_mut
  📝
• impl TryFrom<char> for usize
  📝
• std::iter::Peekable::next_if_map
• std::iter::Peekable::next_if_map_mut
  📝
• x86 avx512fp16 intrinsics
  This excludes those that depend directly on the unstable f16 type.
• AArch64 NEON fp16 intrinsics
  This excludes those that depend directly on the unstable f16 type.
  📝
• <[T]>::element_offset
  📝
• f32::consts::EULER_GAMMA
• f64::consts::EULER_GAMMA
• f32::consts::GOLDEN_RATIO
• f64::consts::GOLDEN_RATIO
  📝

These previously stable APIs are now stable in const contexts:

• f32::mul_add
• f64::mul_add
  📝

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.
  Both core::panic! and std::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_duration will return None for times before the Windows epoch (1/1/1601)
  📝
• Lifetime identifiers such as 'a are 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-prefix given 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-snippets for error emission
  This should preserve mostly the same outputs in rustc error messages.
  📝

[Mark-Simulacrum]

@rustbot ping relnotes-interest-group

[rustbot]

Hi relnotes-interest-group, this issue/PR could use some help in reviewing /
adjusting release notes. Could you take a look if available? Thanks <3

cc @alex-semenyuk @jieyouxu @joshtriplett @Kobzol @lcnr @traviscross

[usamoi]

avx512fp16 intrinsics and neon fp16 intrinsics are partially stabilized but they seem to be missing here, and their version placeholders are not replaced in beta branch.

[Mark-Simulacrum]

Can you link PRs/tracking issues? Not sure why the placeholders wouldn't be replaced (maybe they're in a submodule?)...

[usamoi]

Can you link PRs/tracking issues?

avx512fp16: rust-lang/stdarch#1905
neon_fp16: rust-lang/stdarch#1922
stdarch subtree update: #150639

[Voultapher]

@Mark-Simulacrum could you please adopt #150437 (comment) since the wording is misleading in its current form.

[theemathas]

#140048 and #150202 need a compatibility notes section of some sort.