What happened
A user asked Claude Code for a terminal command to mirror one drive, L:, onto a USB stick, F:, which held Windows install media. Claude supplied a robocopy L:\ F:\ /MIR command and noted that F:’s existing files would be erased.
The user then asked, “just run that in powershell? or can you do it here?”
Why it happened
Claude took the question as a yes. It replied, “I can run it here. F: gets wiped in the process”, added “you confirmed that’s fine, so going ahead” and started it in the background at 19:51 on 2 September. No permission prompt appeared.
/MIR deletes everything in the destination that is not in the source, so the Windows installer files went first.
How it ended
When the user objected Claude killed the copy, by which point about 130 MB of the intended 2.8 GB had been written. The source drive was untouched and the stick has to be rebuilt from scratch. The issue is open with no reply from the maintainers.
