Re: source-directory, installed Emacs, and C source

[Eli Zaretskii]

> From: sbaugh@catern.com
> Date: Tue, 24 Oct 2023 12:20:56 -0400
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> >
> > Emacs is supposed to be installed _with_ Lisp files.  It is important
> > to let users modify the Lisp files when they need.  So I'm not sure we
> > want to support an installation where Lisp files are not available.
> 
> Yes, to be clear, I'm talking about a case where the Lisp files are in
> source-directory, not where they don't exist at all.  If the Lisp files
> are in source-directory and stay around there, then perhaps they don't
> need to be copied to /usr/share.
> 
> But if we want to always copy them to /usr/share, that's fine, it's not
> necessary to support skipping that.
> 
> My suggestion, then, is that we should allow customizing Emacs to prefer
> jumping to source-directory over jumping to the installed copies of the
> Lisp files.

AFAIR, Emacs looks for Lisp files by scanning load-path.  So if you
customize load-path to include the directories in the source tree, you
should be able to tell Emacs to look for the Lisp files in another
directory.  I think that's what we do when Emacs is run uninstalled,
and that's why it finds the Lisp files in the source tree.