Re: package.el, auto-installation, and auto-removal

[Stefan Monnier <monnier@IRO.UMontreal.CA>]

> It would be nice to keep it as a directory structure because they are
> easier to edit:
> .emacs.d/elpa/
> .emacs.d/elpa/archives/
> .emacs.d/elpa/archives/marmalade/
> .emacs.d/elpa/archives/gnu/
> .emacs.d/elpa/archives/user-installed/
> .emacs.d/elpa/archives/user-installed/elnode
> .emacs.d/elpa/archives/user-installed/rcirc

I was thinking of keeping it in a Custom var, since that's easy to edit.
So the equivalent of a Cask file could look like

   % cat CaskNG.el
   (setq package-archives ((gnu ...)
                           (melpa ...)))
   (setq packages-installed '(dash foo bar))
   ...
   %

and you could run your tests with something like

   emacs --batch -l CaskNG.el -f package-install-packages ...

So, my request is for someone to help set up the core of this, i.e. add
the `packages-installed' var (automatically updated by
package-install/delete and friends (I notice now that package-delete is
not a command, surprisingly)), and add the package-install-packages
command (so users can install their packages on a new system simply by
setting packages-installed and then running package-install-packages).
Bonus points for writing `package-gc' which deletes packages not
required by packages-installed.


        Stefan