Re: custom-set-variables fails to set variable

[Richard M. Stallman]

    Why does define-minor-mode need to defvar the mode hook?  There is no
    need to defvar hooks.  `add-hook' can perfectly handle unbound hook
    variables.  I propose that we revert this change in
    define-derived-mode.

I agree, if we can't find a better solution.

Another possible solution is to autoload the defcustoms
for these particular variables.  Would that work?

A more automatic solution could be: define-derived-mode
could automatically produce an autoload definition
of the defvar.  That would solve the problem, right?
It is not normal for update-file-autoloads to generate
an autoload with no autoload cookie, but we could do that.