James N. V. Cash writes: > I was just thinking more about this, and I'm concerned I might need to > change things around a little bit more. The closure that > org-eldoc-get-mode-local-documentation-function now returns under Emacs > 28 doesn't take any arguments and instead lets the > eldoc-documentation-strategy function create its own new callback. > > I think the current approach will appear to work when the documentation > function returns a value directly, but if it uses the callback, then I > think that it won't, since it invokes a new, separate callback. > > I will take another crack at addressing this and send another patch shortly. Indeed, testing with an eldoc backend (a personally hacked-up version of clojure's cider) that actually uses the callback, it wasn't working with the previous approach. I've attached a patch that addresses the previously-mentioned issues as well as this.