This string does not exist in apt or any of the other Ubuntu code I have checked out. If you can reproduce it, do check where it is coming from and reassign it there.
** Package changed: apt (Ubuntu) => ubuntu ** Changed in: ubuntu Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to apt in Ubuntu. https://bugs.launchpad.net/bugs/1982198 Title: apt update: Can not add an empty (zero-length) key to the cache Status in Ubuntu: Incomplete Bug description: When running sudo apt update, I get the following warning after the "Fetched" message: Can not add an empty (zero-length) key to the cache ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: apt 2.0.9 ProcVersionSignature: Ubuntu 5.15.0-41.44~20.04.1-generic 5.15.39 Uname: Linux 5.15.0-41-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.24 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Tue Jul 19 16:44:36 2022 InstallationDate: Installed on 2022-04-26 (84 days ago) InstallationMedia: Ubuntu 20.04.4 LTS "Focal Fossa" - Release amd64 (20220223) SourcePackage: apt UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1982198/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp