The GPL talks about "the preferred form for modification of the software", and I'm starting to think that anything which involves any kind of LLM agent should be including all the text that the user gave to it as well. Prompts, etc.

Of course, even then it's not reproducible and requires proprietary software!

Except the GPL is dependent on the author having copyright over the original software but the output of an LLM may not be covered by copyright as a derivative work.

That breaks "copyleft" entirely.