Using LLMs to find Python C-extension bugs
Summary
The article reviews an experiment using Claude Code-driven tooling to systematically find bugs in Python C extensions, reporting 575+ confirmed bugs across 14 projects and about 140 reproduced from Python. It highlights the cext-review-toolkit with 13 specialized agents, the emphasis on keeping maintainers in control to avoid burnout, and the potential for scalable, high-quality bug reports with feedback loops and improvements such as customized reports and integration with CI tooling. It also discusses maintainers' perspectives, possible enhancements (fuzzing, valgrind coverage), and the broader implications for AI-assisted software assurance in open-source projects.