bug#46256: [feature/native-comp] AOT eln files ignored if run from build tree

[Eli Zaretskii]

> Date: Tue, 09 Mar 2021 14:55:57 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 46256@debbugs.gnu.org, andrewjmoreton@gmail.com, pipcet@gmail.com
> 
> > From: Andrea Corallo <akrl@sdf.org>
> > Cc: pipcet@gmail.com, 46256@debbugs.gnu.org, andrewjmoreton@gmail.com
> > Date: Tue, 09 Mar 2021 07:03:01 +0000
> > 
> > > Can you tell why are we loading the same .eln files more than once?
> > 
> > I guess `load' was called two times on the same filename.
> 
> Is this likely to happen?  Our code generally uses 'require', which
> should avoid that.

Answering my own question here: it can easily happen due to use of
cc-require in cc-*.el files.  Alan, why does CC mode use this
technique? what is the purpose of always loading a Lisp file even if
it was already loaded?