Re: How to un-load a preloaded package?

[Ilya Zakharevich]

On 2010-07-07, Elena <egarrulo@gmail.com> wrote:
> Sorry for my noob answer, but shouldn't:
>
> (add-to-list 'load-path "/path/to/newer/cperl")
>
> take care of that, since `add-to-list' adds paths at the beginning of
> the list (check with `list-load-path-shadows')? Or does `autoload'
> cache the path of the specified file?

Sorry if I was not clear.  The reported behaviour is:

  PRELOADed emacs + load updated version of *.el file at runtime ==> BUGS

  update the version of *.el before PRELOADing + PRELOAD         ==> OK

To add insult to injury, the actual *.el is NOT DUMPED during
preloading; so damage is in something more delicate.  Autoload hints
were considered here as a possible vector of infection; but I have
very little knowledge about how they work...

My question is: can one do anything at runtime to invert effect of
preloading.  Apparently, removing symbols from obarray is not enough.

Thanks anyway,
Ilya

P.S.  Can one re-dump emacs without rebuilding it completely?  I would
      like to verify these reports too...