Evidence gates before full regression in agentic program repair
Teams running coding agents on bug fixes can add a repair gate that preserves failing-test evidence across localization, patching, and validation. The gate should reject unappliable diffs, syntax errors, and build failures before test validation, then rerun the originally failing tests before a full regression suite. Failed attempts should return structured diagnostics to the agent and store the earliest decisive error step for review.
EviACT gives a concrete version of this workflow: it maps RED failing-test evidence to suspect code spans, filters invalid patches with a compile gate, and runs target tests before regression. With GPT-4o, it reports 25.0% resolve rate on Defects4J 2.0, 40.4% on SWE-bench Verified, and 70.1–88.6% lower per-bug API cost where baseline costs are available. TrajAudit adds the audit trail: it diagnoses failed repository-level agent runs by predicting the first step that sent the run off course, with more than 24.4 percentage points better localization accuracy on RootSE while using at least 18% fewer tokens than baselines.
A low-cost rollout is a wrapper around the existing agent runner and CI system. Run it on recent failed agent patches, compare accepted fixes, build-fail rate, full-regression invocations, and tokens per accepted patch, then decide whether to make the gates mandatory for agent-authored pull requests.