Uses tokio-util and rand crates WITHOUT declaring them in the dependency block (prompt said assume tokio/serde/thiserror only). Compiles clean once added — so it's a deps-list omission, not a code bug.
Wrapped output in markdown fences (```toml and ```rust) — required extraction to get runnable code. A submission-hygiene issue, not a logic one.
Full logic audit pending; 0 compile errors with deps declared is the headline.
▮ RECOMMENDED USE
DECISIVE: Rust COMPILES CLEAN (0 errors with deps declared) where Qwen had 7 real compile errors (mpsc::bounded hallucination, ownership moves). The code is structurally sound Rust. Deductions only for undeclared deps + markdown wrapping. Gemma is the better Rust offload pick by a wide margin.
▮ REFACTORED PATCH
# FIX 1 (deps): add to Cargo.toml:
# tokio-util = "0.7"
# rand = "0.8"
# FIX 2: grade_run.py extractor now prefers the ```rust fence; this won't recur.