Spent 3 hours debugging an API that died in 2021: when Cursor's hallucinated legacy code wins the boring way
Full_Collar9026 · reddit · 2026-09-29
The author spent three hours debugging a Python script, only to find Cursor had generated code relying on a LangChain v0.0 endpoint deprecated in 2021. The promise of 10x speed flips to negative productivity the moment the model hallucinates a breaking API change or invents nonexistent parameters—"I'm just an archaeologist digging through 2021 GitHub issues." Until the model reliably reads current docs, they're going back to writing code by hand. A textbook example of how stale training data is the biggest hidden trap for coding agents.
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