EvidenT: An Evidence-Preserving Framework for Iterative System-Level Package Repair

Frequent toolchain updates and the expanding diversity of instruction set architectures (ISAs) have made large-scale system-level software package repair a critical task. Diagnosing and repairing build failures remains challenging due to heterogeneous failure evidence, complex dependency constraints, and architecture-specific build conventions. While recent LLM-based repair methods have shown promise for project-level source code fixes, they struggle with system-level repair where failures involve multi-language artifacts (e.g., build recipes, scripts, and source archives) and require iterative validation through external build services. In this paper, we first conduct a systematic empirical study of real-world system-level build failures. Our findings reveal that 72% of successful repairs primarily involve adjustments to build configurations, dependencies, or environment settings rather than isolated source-code modifications, suggesting that effective repair must prioritize packaging logic and iterative feedback. Motivated by these insights, we propose EvidenT, an evidence-preserving repair framework that decouples iteration-aware evidence management from tool execution. EvidenT comprises (1) an external Build Service for reproducible build execution and feedback; (2) an Evidence-Preserving Repair Controller that performs cross-modal fusion of repair history, knowledge context, and build artifacts; and (3) an automated Repair Orchestrator that executes a suite of modular tools for failure localization and system-level repair actions within a closed-loop validation environment. We evaluate EvidenT on a benchmark of 219 real-world RISC-V package build failures. EvidenT successfully repairs 118 packages (53.88%), substantially outperforming state-of-the-art agentic baselines (20.55%) and direct LLM-based repair (1.83%). To demonstrate its architectural generality, we extend EvidenT to other ISAs by updating only ISA-specific knowledge context. In preliminary experiments, it achieves success rates of 41.77% on aarch64 and 46.99% on x86_64, showcasing its robustness across diverse hardware ecosystems.