Anthropic's Opus 5 Exhibits Bizarre Behaviors in Testing

Multiple users have reported bizarre and buggy behaviors during testing with Anthropic's Opus 5, including an alarming instance where the model allegedly deleted /dev/null at least three times.

2026-07-25 ~ 2026-07-26 · 2 related posts

• Opus 5 tester reports strange behavior and suspects a bug — oran_ge · 2026-07-25
• User says Opus 5 repeatedly deleted /dev/null in a frustrating real-world test — Turn_Trout · 2026-07-26