bug#14926: 24.3.50; Warning "`make-variable-buffer-local' should be called at toplevel"

[Drew Adams <drew.adams@oracle.com>]

> > Is this short enough and clear enough?
> >
> >  "Consider using `make-local-variable' instead"
> >
> > The context (line #) should make it clear what the "instead" refers to.
> 
> That's still confusing.  Why should I consider that?

The message just suggests that you might want to use `m-l-v' instead.

Follow the link to the doc, or use `C-h f make-local-variable' and
`C-h f make-variable-buffer-local' to find out why.  Yes, that's why
it helps to add a manual reference to the msg.

You should not expect a warning message to give you a tutorial.  But
sometimes it can point you to further info that will enlighten you.

> A user already knowing the difference

will either:

a) realize whether or not she made a mistake, by taking 2 sec to
   "consider" which is appropriate here

or:

b) ignore the message, being sure of what s?he is doing.

In both cases the message will have served its purpose (the only
reasonable purpose a message here can have).

> may think "why is there such a (new!) warning?

Now that's a different topic.  ;-)

Emacs is adding warnings all the time.  A user may wonder, indeed.
But that is not particular to this or any that new message.

There is no getting around that, in this case anyway, because there is
nothing new here, besides the fact of Emacs Dev wanting to draw attention
to this possible confusion (which is good to do, especially in the doc).

> Did they change the implementation?  Is there something important I have
> forgotten, or something new I don't know about?

Yes, one wonders.

> I would prefer a sentence like
> 
> "Did you mean `make-local-variable'?"
> 
> which is short and just says: I, Emacs, think you confused those two,
> but it's ok if you know what you're doing.

I disagree that that is as clear, but it's OK by me.  Certainly a lot
better than pointing the user to top-level vs not top-level, which is
a red herring.