To Whom It May Concern

What happened. (1) On a system on which Wireguard was working, I used
the 'TimeShift' program to restore Linux Mint from backup - twice, on
one occasion including within the restore a reinstall of Grub and
rebuild of initramfs. (Points 2-3 that follow apply to both versions of
the restore.) (2) After the restore, WG still worked. (3) I updated the
kernel (on one occasion before rebooting, or another after rebooting).
(4) WG no longer worked. When I tried to reinstall it, it gave
'post-install' messages about how the dkms module was installed already.
All manner of package removal and purging and file deletion failed to
achieve anything - until I discovered that deleting a file in
/var/lib/dkms/wireguard/ (together with 'sudo dkms --reconfigure -a'?)
fixed things.

What should have happened. WG should be able to cope with such a
restore. At worst, it should give the user messages about how to fix the
problem.

System Concerned: Linux Mint 18.3 Cinnamon; WG 0.0.20171211.

Nicholas