When this patch is required When you are using GNU/Linux Devuan v 2 (ASCII), latest (for 2018-04-23) OS provided kernel 4.15.0-0.bpo.2-amd64 and Virtualbox 5.1 (which was latest for ASCII available from devuan repo at moment when this was written) Why this patch is required Because some of Linux kernel function names changed and DKMS vboxdrv rebuild step, which compile new kernel module for VirtualBox, will permanentny fail with compile errors; What you will see without patch VirtualBox will fail to start as there are no kernel module; VirtualBox kernel module will fail to compile; STDERR: The provider 'virtualbox' that was requested to back the machine 'default' is reporting that it isn't usable on this system.