Re: "transient-define-suffix" autoload error ?

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Stefan Monnier via Users list for the GNU Emacs text editor
>  <help-gnu-emacs@gnu.org>
> Date: Wed, 19 Jun 2024 17:36:36 -0400
> 
> >> `.eln` files are indexed by the SHA of the corresponding `.elc`, so if
> >> there's no `.elc` of if it has changed, you should never get some left
> >> over `.eln` file instead.
> >
> > I noticed a few packages had been updated and both the old and new
> > version had eln files in the cache.
> 
> Throwing away old `.eln` files is actually a bit difficult to do
> automatically, so they tend to accumulate, indeed.

Right.  But any new Emacs version you install will create a new
subdirectory in the cache, so one can delete old subdirectories when
they are no longer needed (i.e. when you no longer expect to use the
corresponding Emacs version).  Emacs 29 has the command
native-compile-prune-cache, which will delete all the cache
subdirectories except the one used by the Emacs version of the current
session.

> But Emacs should never load old `.eln`s because when loading a
> `.eln` file is looks for it based on the hash of the `.elc` file it
> would have loaded instead.

I think its hash is based on the .el file instead.  And yes, Emacs
should never load a .eln file that doesn't match the current Emacs
version and the corresponding .el file.