why is git-cherrypick saying nothing to commit

This could be caused by trying to cherry pick a commit that was already integrated/cherry-picked into your current branch.

It's exactly what it says: the changes you're trying to cherry-pick are already wholly contained in the branch you're on. I.e. the result of the cherry-pick is no changes. You can create an empty commit with the --allow-empty flag to indicate that you attempted to cherry-pick, but there were no changes to pull in.