Comment 2 for bug 1840905

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