[OS X Emacs] If you can't update Emacs packages because of a key failure...

[Win Treese]

Aquamacs users,

The signing key for securing Emacs package updates from ELPA recently expired, so you may get an error about this if you try to update packages.

The most straightforward way to deal with this is to install an ELPA package that updates the keys: gnu-elpa-keyring-update. (Note: if you want to be more paranoid about the security of updates, it’s fine to ignore this and to figure out a more satisfying solution.)

But if you didn’t do that before, it won’t install now, because the signing key expired!

Here’s the easiest workaround.

1. Use M-x set-variable, then follow the prompts to set package-check-signature to nil.
2. Run M-x list-packages (or Refresh Packages) from the Package menu
3. Install gnu-elpa-keyring-update
4. Restart Aquamacs

and you should be fine. Technically, you don’t have to restart Aquamacs, but doing so will reset package-check-signature to its previous value. Of course, you could ignore it for the remainder of your session, or set it back yourself.

 - Win