Codegen option: Prefer dynamic linking to static linking.
Unstable Cargo option: Compile the standard library yourself.
Unstable option: debuginfo compression
Unstable option: -Zdump-mir
Unstable option: set dwarf version
Unstable option: fmt-debug
Unstable option: metrics directory
Unstable rustdoc option: Normalize/evaluate types when generating docs
Unstable option: Polymorphization.
Unstable option: Randomize the layout of types.
Unstable option: emit OSC8 hyperlinks in diagnostics
Unstable option: THIR unsafeck
Unstable option: trace-macros
Unstable option: MIR validation
Area: Anything to do with accessibility
Area: Concerning the application binary interface (ABI)
Area: alignment control (`repr(align(N))` and so on)
Area: Custom and system allocators
Area: Associated items (types, constants & functions)
Area: Atomics, barriers, and sync primitives
Area: Attributes (`#[…]`, `#![…]`)
Area: auto traits (e.g., `auto trait Send {}`)
Area: Autovectorization, which can impact perf or code size
Area: bootstrap `config.toml` and the config system
Area: Our favorite opsem complication