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arXiv AI By Alberick Euraste Djire, Iyiola E. Olatunji, Melissa Tessa, Earl T. Barr, Jacques Klein, Tegawend\'e F. Bissyand\'e

Evaluating Inference-Time Defenses Against Package Hallucination in LLM-Generated Code

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The paper investigates how large language models (LLMs) hallucinate nonexistent software packages during code generation and evaluates methods to mitigate this issue. It finds that current evaluation practices overestimate hallucination rates, especially for Python, and that Retrieval-Augmented Generation (RAG) and Self-Refine reduce hallucinations across multiple models and languages. The study also introduces Package Utility (PU) to measure whether defenses preserve useful recommendations and shows that Greedy decoding offers the best trade‑off between mitigation and utility, while adversarial prompts significantly increase hallucination rates, particularly in Ruby.

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