arXiv AI

Do Coding Agents Still Need a Debugger? Frontier-Model-Based Fault Localization at the Accuracy Ceiling

The study evaluates frontier large language models—Sol 6.1, Luna 6, and Qwen 3.8—in their ability to localize faults in LeetCode solutions without tools, with optional debugger assistance, or with encouraged debugger use. Across 610 seeded single‑line faults and five behavior‑preserving transformations, the agents achieved 98.2–99.9% accuracy on original code and 96.7–99.9% on transformed code when no tools were used. Encouraged debugger assistance further improved Luna 6 and Qwen 3.8’s accuracy by 61–63% of remaining errors, albeit at a 14.7–27.0× increase in token usage, while Sol 6.1 maintained 99.9% accuracy regardless of debugger use.

arXiv AI
Oct 9

Can LLMs Fix It Without Code? Toward Automated Verification of No-Code Bug Fixes

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.

By Utku Boran Torun, Veli Karakaya, Eray T\"uz\"un
arXiv AI
Aug 18

When Agentic Executions Fail: Detecting and Localizing Runtime Faults from Telemetry

arXiv:2608. 14680v1 Announce Type: new Abstract: Reliability in LLM-based agentic systems is a property of the whole execution (its tool calls, model calls, guardrails, and inter-agent messages), not of the final answer alone, yet evaluating only task outcomes reveals little about how or why a run fails.

By Chenkai Zhang, Yiran Li, Yifang Tian, Michalis Bachras, Hans-Arno Jacobsen
arXiv AI
Aug 5

CUADebug: Diagnosing and Repairing Computer-Use Agent Failures

arXiv:2608. 02643v1 Announce Type: cross Abstract: Computer-use agents (CUAs) operate real desktop and web interfaces through screenshots, mouse and keyboard actions, and stateful UI feedback, yet their failures remain difficult to diagnose and repair.

By Weijia Zhang, Kunlun Zhu, Zeyi Liu, Yinting Chen, Tianyi Ma, Jiateng Liu, Jiaxun Zhang, Bingxuan Li, Xiangru Tang, Heng Ji, Jiaxuan You
arXiv AI
Aug 6

ORCA-bench: How Ready Are Language Model Agents for Oncall?

arXiv:2607. 28545v2 Announce Type: replace-cross Abstract: Large language models can write, patch, and search code, but oncall root cause analysis (RCA) demands something different: reasoning over noisy metrics, logs, traces, and source code, starting from ambiguous user-facing reports, often hours after the incident began.

By Albert Gong, Kyuseong Choi, Abhineet Agarwal, Jason Schechner, Ryan Huang, Raj Agrawal, Anish Agarwal, Raaz Dwivedi
arXiv AI
Sep 7

When LLM Decompilers Recompile More and Preserve Less

The paper examines how large‑language‑model (LLM) decompilers, which produce clean, idiomatic C code, are currently evaluated mainly on recompilability and passing shipped tests. It shows that these metrics can mask significant behavioral differences: a decompiled function may recompile and pass all tests yet diverge on other inputs or lose disclosed vulnerabilities. To address this, the authors propose Decompile‑Diverge, a behavioral oracle that synthesizes drivers, fuzzes inputs, and compares the decompiled code’s behavior to the original, revealing divergences in up to 13% of cases and exposing gaps in current evaluation suites.

By Chang Liu, Edward Raff, Kristopher Micinski
arXiv Computation and Language
Oct 12

SWE-Duel: Towards a Self-Scaling Arena for Coding Agents

SWE‑Duel proposes a self‑scaling benchmark for coding agents, where tasks and oracles are generated at evaluation time to prevent data leakage and adapt difficulty to participant performance. In the arena, two agents take turns as Red and Blue: Red proposes a feature, injects a subtle bug, and must repair it blind, while Blue reviews the pull request without knowing the bug and must pass all tests. A tournament of 11 model‑harness participants on 15 repositories across five languages showed GPT‑5.5/​Codex CLI as the top solver and Claude Opus 4.8/​mini‑swe‑agent as the top task author, with newer model versions producing harder tasks for older ones.

By Wei Minn, Zhensu Sun, Lwin Khin Shar, David Lo