rust-build-optimization

Use when a Rust or Cargo build is slow and the user wants it diagnosed or sped up: profiling compile times with cargo --timings or -Zself-profile, finding whether the bottleneck is dependencies, codegen/LLVM, linking, or one oversized crate, and applying targeted fixes such as faster linkers (lld, mold, wild), incremental compilation, dev/release profile tuning, workspace splitting, Cranelift, the nightly parallel frontend, or CI caching with sccache. Also for reviewing .cargo/config.toml or Cargo.toml profile settings for build speed. Not for making the compiled program run faster (runtime optimization), general Rust coding or debugging questions, or non-Rust build systems.