Also, every single interpreter error has an entire corpus of StackOverflow-esque fix suggestions alongside it, and the model has been fine-tuned to minimize such errors on the first try. This hasn't been done for more obscure languages. You'll likely take more turns, on average, to get a working output, even if your problem is fully verifiable via test input/outputs - and if it's not verifiable, you don't want the "attention" of the model focused on syntax rather than the solution.