I'm sorry, I think I jumped the gun on this one. Do check if you nave universe enabled as mentioned previously, but also check if you have security and updates.
The available libkrb5-3 and krb5-user packages in bionic are: libkrb5-3 | 1.16-2build1 | bionic libkrb5-3 | 1.16-2ubuntu0.1 | bionic-security libkrb5-3 | 1.16-2ubuntu0.1 | bionic-updates krb5-user | 1.16-2build1 | bionic/universe krb5-user | 1.16-2ubuntu0.1 | bionic-security/universe krb5-user | 1.16-2ubuntu0.1 | bionic-updates/universe -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to krb5 in Ubuntu. https://bugs.launchpad.net/bugs/1840905 Title: krb5-user seems not installing on Bionic Status in krb5 package in Ubuntu: New Bug description: I am not able to install kerberize-client on a Ubuntu 18.04.2 LTS. Due of krb5-user that depends of libkrb5-3. libkrb5-3 (= 1.16-2build1) but 1.16-2ubuntu0.1 is the latest version. # apt-get install kerberize-client Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: kerberize-client : Depends: krb5-user E: Unable to correct problems, you have held broken packages. # apt-get install krb5-user Reading package lists... Done Building dependency tree Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: krb5-user : Depends: libkrb5-3 (= 1.16-2build1) but 1.16-2ubuntu0.1 is to be installed E: Unable to correct problems, you have held broken packages. # apt-get install libkrb5-3 Reading package lists... Done Building dependency tree Reading state information... Done libkrb5-3 is already the newest version (1.16-2ubuntu0.1). To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/krb5/+bug/1840905/+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