Accepted but Wrong: Silent Failures of LLM Code Repairs after API Migrations
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The study examines how large language models (LLMs) repair code after runtime or API migrations, revealing that many repaired procedures run without errors yet produce incorrect results. Across 73 tasks and 60 documented changes in CPython, Node.js, and SQLite, the authors found that typical test inputs allowed 41% of wrong repairs to pass, while targeted edge inputs reduced this to 6–7%. Even with additional hard distractors and blind model writers, a significant fraction of incorrect repairs still passed the preregistered tests.
The paper "Poison Valleys: Diagnosing Path-Dependent Failure in LLM Code Repair" investigates why large language model (LLM) code‑repair agents sometimes produce incorrect patches. By analyzing 1,844 model requests on two synthetic Python tasks—PersistQueue and Dijkstra—the authors trace how misconceptions in a model’s hypothesis or implementation plan lead to specific software obligation violations. They find that shifting a misconception from hypothesis to plan increases failure rates by roughly 30% for both tasks, revealing distinct, model‑dependent failure patterns linked to upstream misunderstandings.
The paper investigates hallucination in large language model–based automated program repair (APR). It defines hallucination as producing patches or intermediate artifacts that are not grounded in available repair evidence, and analyzes it across final patches and intermediate tasks such as triggering test case identification, line coverage prediction, and additional test case generation. Experiments on 832 Defects4J bugs show that only 21.0%–55.9% of patches pass the developer test suite, with 72.7% of sampled repairs exhibiting hallucinations, often due to incorrect causal localization or repair strategies.
The paper investigates whether large language models (LLMs) can automatically verify no-code bug fixes—solutions that instruct users to change settings, upgrade versions, or alter workflows—by executing them in a real browser environment. Using 322 fixes from a benchmark, the study tests three executor agents (OpenCUA‑72B, Claude Sonnet 5, and Meta’s Muse Glimmer) and finds that only 17.6% of issues could be set up and passed sanity checks, with resolution rates ranging from 14.6% to 49.7% depending on the executor. Even the best configuration resolved fewer than half of the fixes, and executor choice significantly affected outcomes, highlighting the need for execution-based verification before such fixes reach users.
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