Faster linking times with 1.90.0 stable on Linux using the LLD linker

Rust's upcoming 1.90.0 release on September 18, 2025, will default to using the faster LLD linker for x86_64-unknown-linux-gnu targets, significantly improving linking times, with a drop in incremental build linking times by 7x. Developers are encouraged to test this beta version now and report any issues. While LLD offers considerable performance benefits, it may not be fully compatible with GNU ld, but can be reverted back if needed.