Fixing the error "gpg: Can't check signature: No public key" (2024)

If you're trying to install eev with M-x list-packages but you're getting the error "gpg: Can't check signature: No public key", as in the screenshot below,

then you need to install the new public key and then eev. There are two ways to do that.

Way 1

If you are a total beginner who is following the instuctions in (find-windows-beginner-intro) and you got this error, you probably installed Ubuntu in WSL instead of installing Debian, and the best solution is to delete your Ubuntu image, install a Debian image, and make Debian the default... the "Way 2" below will mostly work, but some things in later steps will break!!!

Way 2

Copy and paste the 9-line progn below to an Emacs buffer and then execute it by typing `C-e C-x C-e' in the line with its closing parenthesis:

(progn
  (package-initialize)
  (setq package-check-signature nil)
  (package-refresh-contents)
  (package-install 'gnu-elpa-keyring-update)
  (setq package-check-signature 'allow-unsigned)
  ;;
  (package-install 'eev)
  )

Links

https://www.reddit.com/r/emacs/comments/bn6k1y/updating_gnu_elpa_keys/
  (find-es "emacs" "gnu-elpa-keyring-update")
  (find-lean4-intro "6. Install lean4-mode")

(Announcements: eev mailing list)