Definition
Techniques and tooling changes that reduce Rust project compile and check times — critical for large monorepos and CI pipelines where dependency graphs serialize work across cores.
Key Points
- 2026-10-04: headstart experimental patches yield 13–54% check speedups on real projects via early metadata emission (2026-10-04-rust-headstart-faster-builds)
- Existing: Cargo pipelined compilation, parallel frontend (
-Zthreads), incremental compilation, sccache/mold linkers - Benefit scales with idle cores during metadata waits — wide dependency graphs gain most
- Experimental patches require custom rustc/Cargo builds — not production-ready