Loc2Repair: A Framework for Evaluating the Impact of File-Level Issue Localization in Repo-Level LLM Repair
Summary
Loc2Repair is a modular evaluation framework designed to analyze repository-grounded LLM repair pipelines by isolating file-level issue localization as an upstream variable. The framework decouples localization and repair stages under a shared runtime, artifact schema, and evaluation harness, enabling controlled comparisons of different localization models and repair backbones. Evaluating three repair backbones on 500 SWE-bench Verified instances, Loc2Repair demonstrated that explicit localization consistently improves resolved rates. Pooled performance rose from 44.7% for baseline repair to 48.9% with Pred-Qwen4B, 49.1% with Pred-Gemma4E4B, and 52.4% with gold localization. Additionally, localization reduced mean elapsed time, with pooled paired analysis showing decreases of 100.94s, 52.25s, and 154.45s for the respective localization settings, though token usage varied. The study concludes that file-level localization is a significant lever for improving repair effectiveness and latency, yet substantial headroom remains even with oracle-level guidance.
Key takeaway
For MLOps Engineers and Research Scientists designing or evaluating repository-grounded LLM repair agents, you should prioritize integrating a dedicated file-level localization stage. Explicit localization consistently improves resolved rates and often reduces mean elapsed time, as shown by gains from 44.7% to 52.4% with gold guidance. However, recognize that localization is not the sole bottleneck; further decomposition of repair pipelines into specialized stages will yield additional improvements.
Key insights
File-level localization consistently improves LLM-based repository repair effectiveness and latency, but is not the sole bottleneck.
Principles
- Explicit localization enhances LLM repair effectiveness.
- Stage-aware evaluation reveals specific failure modes.
- Localization quality does not monotonically translate to downstream gains.
Method
Loc2Repair decouples localization and repair stages, using a shared runtime and evaluation harness to compare different localizers and repair backbones under matched conditions, isolating localization as an experimental variable.
In practice
- Integrate explicit file localization into LLM repair pipelines.
- Use lightweight localizers for upstream guidance.
- Decompose repair into specialized stages beyond localization.
Topics
- Issue Localization
- Repository-Grounded Repair
- LLM Coding Agents
- SWE-bench
- Evaluation Frameworks
- Software Engineering Agents
Code references
Best for: AI Scientist, Research Scientist, MLOps Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.SE updates on arXiv.org.