To install this package, run in Emacs:
M-x package-install RET gnu-elpa-keyring-update RET
This package updates the GPG keys used by the ELPA package manager (a.k.a `package.el') to verify authenticity of packages downloaded from the GNU ELPA archive. Those keys have a limited validity in time (for example, the first key was valid until Sep 2019 only), so you need to install and keep this package up to date to make sure signature verification does not spuriously fail when installing packages. If your keys are already too old, causing signature verification errors when installing packages, then in order to install this package you can do the following: - Fetch the new key manually, e.g. with something like: gpg --homedir ~/.emacs.d/elpa/gnupg --receive-keys 066DAFCB81E42C40 - Modify the expiration date of the old key, e.g. with something like: gpg --homedir ~/.emacs.d/elpa/gnupg \ --quick-set-expire 474F05837FBDEF9B 1y - temporarily disable signature verification (see variable `package-check-signature').