BugProof — Verified Regression Tests from Vague Bug Reports | Frontier Engineering Challenge

BugProof turns vague software bug reports into verified failing regression tests. The core idea is simple: A failing test is not evidence of reproduction. The failure has to be the right failure. BugProof combines LLM-based test generation with deterministic execution gates, evidence grounding, bounded repair, and offline oracle evaluation. On the 12-case evaluation corpus, the precision-oriented D_exec policy: • reduced false delivered reproductions from 3 → 1 • increased claim precision from 75% → 80% • reduced coverage from 100% → 41.7% • delivered 4 correct reproductions vs. 9 under the coverage policy The result exposes an important engineering trade-off: Abstention is not free. BugProof preserves frozen candidates, trajectories, raw coding-agent traces, replayable evaluation evidence, and integrity hashes for reproducibility. Built for the Frontier Engineering Challenge 2026.