Translate or Replay? Two AI-Assisted Rewrites Compared — ggblab version 1 → version 2 (n = 1) and Bun Zig → Rust: what each kept, what served as the oracle, what escaped, and what code volume measures
Technical report comparing two software rewrites carried out with AI coding agents in 2026. Bun, a JavaScript runtime, was translated from 535,496 lines of Zig into about 780,000 lines of Rust in eleven days by about 64 concurrent agents, gated by the existing test suite; the vendor reports 19 known regressions introdu...