MEP-56 note 12: Risks and alternatives

Author: research pass for MEP-56 (Mochi to Ruby transpiler). Date: 2026-05-29 (GMT+7).

Risk register: mruby subset gaps (no Thread, no Data.define, limited stdlib), TruffleRuby polyglot API changes, Tebako codesigning on macOS, CRuby 4 YJIT default affecting benchmark baselines, cassette drift. Rejected alternatives: Opal-style compilation (browser-only), warbler (JVM-only), no-gem single-file (no pkg.go.dev equivalent in Ruby ecosystem).

Full research note content for MEP-56 note 12.