I've only had great luck with the LLMs(chatgpt 3o) generated Perl code. It was able to synthesize code for a GTK2/3 application fairly consistently, without generating any syntax errors. Most of the code worked as described, and it seemed to make more mistakes misunderstand my descriptions of features rather than when implementing them. My colleagues suggested it was because Perl's popularity had fallen significantly before 2016, and the training data set might've had much less noise.