Claude nukes a developer’s 700 GB home directory while testing deletion safeguards; Anthropic’s safety harness may have contributed by automatically downgrading the model to Opus 4.8 before a fatal variable collision

AI coding agent Claude Fable deleted roughly 700 GB from a developer’s home directory while testing a cleanup script.

A reused variable and flawed safety-test logic, triggered during a downgrade from Opus 5 to Opus 4.8, redirected the operation from /tmp to the home directory.

The developer recovered most data through Git, Nix data, and session logs, but the incident highlights the risks of destructive autonomous tasks without strong isolation and backups.