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

[Philip Kaludercic]

Eli Zaretskii <eliz@gnu.org> writes:

>> 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?

If you use regular package-* functions, upgrading always deletes and old
version when the new one is installed, so IIRC having two separate
versions of a package installed has to be the result of some manual
intervention.

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

M-x package-autoremove should take care of them.