Language edition/toolchain drift

Rust 2024 unsafe extern blocks edition guide

Edition migration turns a previously valid FFI declaration into a compiler error.

search-observedRust 2024RustLanguage edition/toolchain driftrust2024

Agent Quick Fix

Source may compile under an older edition/toolchain; current edition migration rules and tool metadata are external to the repo's immediate error context.

Product: Rust 2024
Current-contract area: FFI `extern` block requires `unsafe`
Likely root cause: Edition migration turns a previously valid FFI declaration into a compiler error.
Repair direction: Verifier checks idiomatic migration while preserving cross-version intent where required.

Validation Status

Codex searched organically in the validation run. No no-web counterfactual is attached to this page yet.

Symptom

Edition migration turns a previously valid FFI declaration into a compiler error.

Why This Happens

Source may compile under an older edition/toolchain; current edition migration rules and tool metadata are external to the repo's immediate error context.

Verification

Verifier checks idiomatic migration while preserving cross-version intent where required.

Common Wrong Fixes

Changing local code without checking the current external contract.
Retrying the same install, build, or API call with no version/source change.
Applying a broad unsafe bypass when a narrow compatibility fix is available.

Codex Search Keywords

These are the search terms observed in a neutral Codex validation run for this failure shape.

Rust 2024 unsafe extern blocks edition guide
https://doc.rust-lang.org/edition-guide/rust-2024/unsafe-extern.html