Leapp fails to mount /var/log properly and ends in the emergency shell

Issue

The problem can manifest itself in various ways. Among others:

localhost upgrade[804]: mount: mount point /var/log does not exist

localhost upgrade[804]: IOError: [Errno 2] No such file or directory: '/var/log/leapp/dnf-plugin-data.txt'

Jun 15 05:03:46 localhost upgrade[804]: IOError: [Errno 2] No such file or directory: '/var/log/leapp/answerfile'

localhost upgrade[660]: IOError: [Errno 2] No such file or directory: '/var/log/leapp/leapp-upgrade.log'