Re: void variable

[Richard Stallman]

    Maybe we could arrange for defvar to burp a warning if the var is currently
    let-bound?

That sounds like a good idea.  It should be possible to do this
by searching the specpdl.

       Maybe we could arrange for defvar to burp a warning if the var is 
currently
       let-bound?

    Just to be sure, I assume you mean a compiler warning?

This is a load-time occurrence; the compiler cannot detect it.
It would have to be detected at run time.  The warning could
use display-warning.

      defvar-ing
    let-bound variables is OK for autoloaded variables.

The warning could be issued only when the global binding that was
shadowed by the let-binding was unbound.  That will never be the case
for autoloaded variables.

      It is also OK for
    `(defvar foo)''s that are just there to pacify the compiler.

Yes, that case should not warn.