Rust Enables Polonius Alpha on Nightly Builds, Targets 2026 Stabilization
Updated
Updated · InfoWorld · Aug 8
Rust Enables Polonius Alpha on Nightly Builds, Targets 2026 Stabilization
2 articles · Updated · InfoWorld · Aug 8
Summary
Polonius Alpha is now enabled by default on Rust nightly releases for testing, with the team aiming to fully stabilize the borrow checker later this year.
Jack Huey said no known blocking issues remain and performance is generally acceptable, but nightly rollout is meant to surface serious regressions, unsoundness and weak diagnostics before stabilization.
Developers who hit problems can report them on GitHub or Zulip, and can switch back to the stable NLL checker with -Zpolonius=off in rustc, RUSTFLAGS or Cargo config.
Polonius has been in development since 2018; a 2023 redesign minimized changes to Rust's existing NLL implementation while aiming to accept more sound code.