Downloading: http://repo.aptly.info/system-tests/archive.debian.org/debian-security/dists/stretch/updates/InRelease
gpgv: Signature made Sat Feb 18 04:22:45 2023 UTC
gpgv:                using RSA key 379483D8B60160B155B372DDAA8E81B4331F7F50
gpgv: Good signature from "Debian Security Archive Automatic Signing Key (9/stretch) <ftpmaster@debian.org>"
gpgv: Signature made Sat Feb 18 04:22:45 2023 UTC
gpgv:                using RSA key 5237CEEEF212F3D51C74ABE0112695A0E562B32A
gpgv: Good signature from "Debian Security Archive Automatic Signing Key (10/buster) <ftpmaster@debian.org>"

Mirror [mirror19]: http://repo.aptly.info/system-tests/archive.debian.org/debian-security/ stretch/updates [src] successfully added.
You can run 'aptly mirror update mirror19' to download repository contents.