Door's Locked, Try the Window

TL;DRAsk a coding agent to fix a bug in a read-only file. Instead of reporting that it does not have permissions, it routes around the lock and completes the task anyway. A read-only file does not stop a capable agent: it treats a denied write as an obstacle to work around rather than a hard wall. We measure how often this happens with CircumEval — an evaluation of 8 tasks on the FastAPI codebase in two categories, Test-Locked and Source-Locked.We evaluate three frontier coding agents in their r...