Re: Changes to make in elpa-packages file for nongnu elpa

[Eli Zaretskii]

> From: Philip Kaludercic <philipk@posteo.net>
> Cc: emacs-devel@gnu.org
> Date: Tue, 15 Aug 2023 16:55:03 +0000
> 
> +*** New command to start Emacs only with specific packages
> +The command 'package-isolate' is equivalent to starting Emacs with the
> +-Q flag and loading specific packages (and their dependencies)
> +manually.

Seems strange to me to have a command to start another Emacs.  Why not
implement this as a command-line option instead?  That would be
consistent with the several options we already have, like -q, -Q, -D,
which already contrl what happens at startup.

> +        (let* ((real (package-desc-dir package))
> +               (link (expand-file-name (file-name-nondirectory real) elpa)))
> +          (make-symbolic-link real link t)

Using symbolic links makes the program less portable, so it is best to
avoid them.

> +    (apply #'start-process (concat "*" name "*") nil
> +           (append (list (or (emacs-executable) "emacs")

I don't think it's a good idea to invoke just "emacs", it could be a
completely different version of Emacs.

> +DEFUN ("emacs-executable", Femacs_executable, Semacs_executable, 0, 0, "",
> +       doc: /* Return a string with the file name of the Emacs executable.
> +If this is not known, nil will be returned instead. */)
> +  (void)

I don't understand why you need this primitive.  What's wrong with the
usual paradigm we use everywhere else:

  (expand-file-name invocation-name invocation-directory)