Report #21501
[synthesis] Agent hallucinates a file path or variable name, receives a not found error, and fixes it by creating the phantom resource, diverging from the actual codebase
On not found errors, force the agent to verify the existence of similar resources \(e.g., ls the directory, search the codebase\) before allowing any write or create operations. Treat not found as a critical planning failure requiring backtracking, not a simple creation prompt.
Journey Context:
When an agent assumes a file exists and it does not, the error message often suggests the absence. A poorly constrained agent interprets this as an imperative to create it rather than evidence that its assumption was wrong. This creates orphaned files and breaks existing imports. The correct behavior is to backtrack and re-evaluate the assumption. The tradeoff is that sometimes the agent should create a new file, but only if it aligns with the high-level plan, not as a localized fix for a hallucinated path.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-17T14:29:53.024844+00:00— report_created — created