@eniko this one hits particularly well, as I have tried copilot on GitHub web interface to ask it about my language, to see how far it could go (spoil: I stopped pretty early in my investigation)

It knew it is a lisp inspired language (probably was trained on the readme, at least, since the phrase « lisp inspired » is in the 1st or 2nd paragraph), but spit false facts, and code that isn’t even valid, as if it was Scheme or Common Lisp…
I knew it would be bad, but didn’t expect it to be that bad!