>> changes on related things. Maybe you could explain the rationale
>> behind the test so that I can take that into account when I'm fixing
>> the derived modes?
> The additional check is only relevant when compiling unbundled packages
> (the bundled packages are never used with a different Emacs version).
But people compile packages with a new Emacs and then run them with an
old Emacs? I thought we only try to support the other way around.
> So you shouldn't worry about it when modifying emacs/lisp/**/*.el files.