Downloading http://archive.debian.org/debian-security/dists/stretch/updates/InRelease... Success downloading http://archive.debian.org/debian-security/dists/stretch/updates/InRelease gpgv: RSA key ID 331F7F50 gpgv: Good signature from "Debian Security Archive Automatic Signing Key (9/stretch) " gpgv: RSA key ID E562B32A gpgv: Good signature from "Debian Security Archive Automatic Signing Key (10/buster) " Mirror [mirror19]: http://archive.debian.org/debian-security/ stretch/updates [src] successfully added. You can run 'aptly mirror update mirror19' to download repository contents.