Line-ranked repair candidates for failed coding-agent runs
A coding-agent repair loop can give the model a ranked set of likely faulty lines before it asks for another edit. FLARE shows the concrete shape: a lightweight diagnostic model scores lexical units, pools them to line-level suspiciousness, prompts refinements against the top-k lines, runs tests, and keeps the candidate with the best execution outcome. With k=10, FLARE improved Pass@1 across five base models on LiveCodeBench and BigCodeBench, while its diagnostic model reached 67% Top-1 and 89% Top-10 localization accuracy on 100 LiveCodeBench tasks.
The workflow fits teams already collecting failed agent patches in CI. Store the failing program, test output, token probabilities if available, ranked suspicious lines, generated candidates, and test outcomes. Add a small behavior check for proposed edits: Neural Change Prediction reports that mutation-output pairs can train a model to predict the likely effect of a code change, with fine-tuned GPT-4.1 reaching 95% accuracy for output-change prediction on single Python mutations. A pilot can replay recent failed generations and compare execution-only repair against line-ranked candidate search on pass rate and review minutes per accepted fix.