rustc-basics

Rust compiler skill for systems programming. Use when selecting RUSTFLAGS, configuring Cargo profiles, tuning release builds, reading assembly or MIR output, understanding monomorphization, or diagnosing compilation errors. Activates on queries about rustc flags, Cargo.toml profiles, opt-level, LTO, codegen-units, target-cpu, emit asm, MIR, or Rust build performance.