bug#46790: 28.0.50; make install with native-comp branch

[Eli Zaretskii]

> From: Thierry Volpiatto <thievol@posteo.net>
> Date: Fri, 26 Feb 2021 08:35:30 +0100
> 
> giving a try to native-comp branch.
> 
> I install Emacs generaly with:
> 
> make install bindir=/usr/local/sbin/emacs-28.0.50 
> infodir=/usr/local/share/info-28.0.50
> 
> This always worked fine.  However with native-comp branch, I have to
> manually add a symlink of "/usr/local/lib/emacs/28.0.50/native-lisp/" to
> "/usr/local/sbin" otherwise I endup with an error:
> 
> thierry@IPadS340:/usr/local/sbin/emacs-28.0.50$ ls
> ctags  ebrowse  emacs  emacs-28.0.50  emacsclient  etags
> thierry@IPadS340:/usr/local/sbin/emacs-28.0.50$ ./emacs-28.0.50
> emacs: 
> /usr/local/sbin/emacs-28.0.50/../native-lisp/28.0.50-40158ec0/window-0d1b8b93-738411b0.eln:
>  cannot open shared object file: No such file or directory
> thierry@IPadS340:/usr/local/sbin/emacs-28.0.50$ ./emacs
> emacs: 
> /usr/local/sbin/emacs-28.0.50/../native-lisp/28.0.50-40158ec0/window-0d1b8b93-738411b0.eln:
>  cannot open shared object file: No such file or directory

Hmm... I'm not sure we can resolve this in any other way, although we
should try.  What worked for you with previous versions was just a
side effect of the implementation detail: how Emacs finds the files it
needs when it starts.  The *.eln files bring more restrictions to the
table, and it could very well be that the symlink trick will be the
only practical solution to such a non-standard installation.

A possible solution is to set EMACSNATIVELOADPATH in the environment.

Alternatively, you could modify your Emacs to look in the correct
directory by default.