Three bugs my AI agents couldn't fix

Short summary

The author built a Rust terminal multiplexer (wimux) mostly with AI agents and details three bugs the agents couldn't crack: terminal glyph corruption from resize bursts, focus loss when clicking non-focusable sidebar elements, and typing lag from unmerged PTY write chunks. Each fix required human insight—observing at the correct system layer, building targeted reproduction harnesses, and distinguishing accounting decisions from correctness bugs. The post is a practical case study in where AI coding agents hit walls.

• •Three real bugs in a Rust terminal app that AI agents failed to diagnose
• •Key lesson: agents struggle with multi-layer system bugs requiring cross-layer observation
• •Human debugging skills—reproduction harnesses, layer isolation—remain essential

Generated with AI, which can make mistakes.