AotokitsuruyaDeveloping Kobako has surfaced quite a few interesting cases. Continuing from the previous post, Building Kobako with AI: Will It Eventually Crash?, I ran into yet another new problem afterward—and this time it was the Segmentation Fault error I had always dreaded seeing during development. That signals a high chance something went wrong in the non-Ruby territory between Rust and WebAssembly.
AotokitsuruyaAt RubyKaigi 2026 this year, while chatting with friends about Harness Engineering and the Sandbox aspect of it, I realized that Ruby still lacks a solid solution in this space. On the second night, I happened to be assigned to the druby (Ruby’s built-in distributed object system) group at the Code Party — and that’s how the idea for Kobako was born.
AotokitsuruyaThe Ralph Loop technique — a trick for making AI Coding Agents automatically repeat execution — was popular last year, but I didn’t trust whether it was safe enough or sufficiently stable.
A few months ago, Claude Code’s update introduced the /loop skill, which essentially uses Claude Code’s built-in Cron tool to repeat specific prompts at fixed intervals, achieving a similar effect. At least it’s safer and more controllable.
However, things are rarely that simple.