The Wire · Showcase
CONST EVALUATION OVERHAUL LANDS; CARGO WINDOWS TOKEN BUG BLOCKS REGISTRY ACCESS
By RepoJournal · Filed · About Rust
The compiler just shipped a major const evaluation refactor that removes UnevaluatedConstKind::def_id, while cargo's registry authentication is broken on Windows due to a carriage return parsing bug that's been live since 1.96.
The const evaluation work [1] lands as part of the larger effort to decouple const handling from DefID, removing the footgunny is_const method [2] in the process. This is foundational work that unblocks feature-specific const improvements down the line. Meanwhile, cargo has a production blocker [3]: Windows token helpers emit \r\n line endings, but the adaptor only strips \n, leaving a trailing \r that http::HeaderValue now rejects. Users on Windows trying to authenticate with the registry hit "failed to parse header value" and can't proceed. The fix is simple - trim the \r after \n - but this has been live since cargo 1.96's registry refactor and needs immediate patching. On the testing front, the rustdoc build saw cleanup [4] and test suite reliability improved [5] [6] with XFS filesystem fixes and diagnostic ordering relaxation for parallel frontends. libc's CI got routine infrastructure updates [7] [8] [9], and bors bumped askama to 0.16.0 [10] [11]. crates.io-index saw five routine package updates across sp1 tooling and ui components [12] [13] [14] [15] [16].
Action items
- → Patch cargo immediately for Windows registry authentication - users are blocked rust-lang/cargo [immediate]
- → Review const evaluation changes [ref:6] [ref:7] if you maintain feature-specific const handling rust-lang/rust [plan]
- → Monitor libc CI infrastructure updates for test stability rust-lang/libc [monitor]
References
- [1] Auto merge of #157374 - khyperia:remove-UnevaluatedConstKind-def_id, r=BoxyUwU rust-lang/rust
- [2] Remove possibly footgunny `is_const` method rust-lang/rust
- [3] fix: strip CR from `cargo:token-from-stdout` ↗ rust-lang/cargo
- [4] rustdoc: Remove unnecessary fast path rust-lang/rust
- [5] Rollup merge of #156762 - ferrocene:hoverbear/xfs-test-fix, r=Mark-Simulacrum rust-lang/rust
- [6] Rollup merge of #157300 - zetanumbers:fix-note-on-different-line-tests, r=petrochenkov rust-lang/rust
- [7] build(deps): bump vmactions/solaris-vm from 1.3.6 to 1.3.7 ↗ rust-lang/libc
- [8] build(deps): bump taiki-e/install-action from 2.81.2 to 2.81.8 ↗ rust-lang/libc
- [9] build(deps): bump vmactions/netbsd-vm from 1.3.9 to 1.4.0 ↗ rust-lang/libc
- [10] Merge pull request #760 from GuillaumeGomez/update-askama rust-lang/bors
- [11] Update `askama` dependency to `0.16.0` version rust-lang/bors
- [12] Update crate `sp1-lib` rust-lang/crates.io-index
- [13] Update crate `nice-plug` rust-lang/crates.io-index
- [14] Update crate `sp1-cli` rust-lang/crates.io-index
- [15] Update crate `atomr-agents-context` rust-lang/crates.io-index
- [16] Update crate `zng-wgt-ansi-text` rust-lang/crates.io-index
FAQ
- What changed in Rust on June 8, 2026?
- The compiler just shipped a major const evaluation refactor that removes UnevaluatedConstKind::def_id, while cargo's registry authentication is broken on Windows due to a carriage return parsing bug that's been live since 1.96.
- What should Rust teams do about it?
- Patch cargo immediately for Windows registry authentication - users are blocked • Review const evaluation changes [ref:6] [ref:7] if you maintain feature-specific const handling • Monitor libc CI infrastructure updates for test stability
- Which Rust repositories shipped on June 8, 2026?
- rust-lang/rust, rust-lang/cargo, rust-lang/libc, rust-lang/bors, rust-lang/crates.io-index