ubuntu-archive-keyring for Debian --------------------------------- This package does not enable Ubuntu's GPG keys as system trusted keyring by default (since 2016.05.13-2). If you want to do so, run below command. . # dpkg-reconfigure --priority=low ubuntu-archive-keyring . However, it is not recommended because not necessary in most cases. -- Hideki Yamane Wed, 29 Aug 2018 16:30:23 +0900