Rust update fixes ‘forever’ compilation

The Rust Team has published a point release update, Rust 1.84.1, to address a few regressions in last month’s Rust 1.84 release, including fixing painfully slow compilation related to the next-generation trait solver.

Announced January 30, Rust 1.84.1 can be accessed as an update by running the command rustup update stable.

With the new trait solver, the goal is to check whether a given trait bound is satisfied, most notably when type checking the body of potentially generic functions. However, the new feature resulted in unexpectedly slow compilation in Rust 1.84. This is fixed with Rust 1.84.1.

In a second regression addressed by the 1.84.1 update, errors have been fixed for overlapping impls in incremental builds. A third regression patched involves resolving compiler errors in duplicate-crate diagnostics. And a fourth fixes missing debug info when LLVM’s location discriminator value limit was exceeded.

Several fixes also were made for those building Rust from source, including resolving symlinks of LLVM tool binaries before copying them and making it possible to use ci-rustc on tarball sources.

The follow-up to Rust 1.84, Rust 1.85, is due February 20, with capabilities including stable support for async closures.