bug#63757: 29.0.91 order of package paths changed: random old versions of packages in load-path

[Eli Zaretskii]

> From: Евгений Бойков <artscan@list.ru>
> Date: Sun, 4 Jun 2023 18:43:13 +1000
> Cc: monnier@iro.umontreal.ca, philipk@posteo.net, 63757@debbugs.gnu.org
> 
> > I wonder how come this issue never came up until now, in all the time
> > since commit fb87d500, 9 months ago?  What are you, Евгений, do that
> > bumps into this issue, that other people don't do?  Or does this
> > affect only very specific packages?
> 
> I moved my everyday working emacs instance to 29.0.91 and got almost 2% 
> completely broken
> packages.
> I rarely delete really old versions from my ~/.emacs.d/elpa.
> If your package-user-dir is cleaned more often, you may not notice that your 
> loaded packages have
> slightly different old versions.
> This can affect any package if it has few versions.

So you are saying that other people mostly delete old versions from
~/.emacs.d/elpa/, and that's why this problem was not reported until
now, is that right?

What are our recommendations, if any, for cleaning up old versions of
ELPA packages?