Fix chrF fallback so English wiki garbage fails translation_success

Sacrebleu errors used to fall back to set-overlap unigrams, so any English hyp scored ~70–80 against English refs and SFT reported success 1.0. Use count-based char n-grams, keep BLEU failures from clobbering chrF, and print a few hyps during eval.
2026-08-26 14:23:22 +08:00
parent 5a7d949b01
commit 5cc0555563
4 changed files with 48 additions and 14 deletions
@@ -339,6 +339,8 @@ def main() -> None:
                    )
                    printable = {k: v for k, v in out.items() if k != "hyps"}
                    print(printable)
+                    for i, hyp in enumerate((out.get("hyps") or [])[:2]):
+                        print(f"   hyp[{i}] {hyp}")
                    if tracker is not None:
                        tracker.log(
                            {