Devtools | Sebastian Spicker

2026

1 article

5 Oct 2026 The Day Claude Decided to Delete My Whole Codebase On 5 October 2026, a unit test run by a coding subagent recursively deleted every checkout under my projects directory in well under two minutes. No model “decided” anything. An orchestrating model wrote a guard rule of the form “anything outside the repository is allowed”, a test handed that guard the repository’s parent directory, and nothing between the test and the filesystem said no. This is the incident, the recovery, and the four layers that now stand where there were none. agentic-codingclaude-codeincident-report

2025

1 article

4 Dec 2025 Constraining the Coding Agent: The Ralph Loop and Why Determinism Matters In late 2025, agentic coding tools went from impressive demos to daily infrastructure. The problem nobody talked about enough: when an LLM agent has write access to a codebase and no formal constraints, reproducibility breaks down. The Ralph Loop is a story-driven harness intended to bound that variability through one model invocation per attempt, scoped writes, and atomic state. These constraints make runs easier to inspect; they do not make an unpinned model deterministic. agentic-codingautomationsoftware-engineering