build breakage on Ubuntu 19.10

[Jason A. Donenfeld]

Hi all,

The Canonical kernel team is a bit behind in deploying fixes (i.e.
bumping the wireguard package version) for recent breakage they
introduced. As a result, WireGuard will entirely stop working when
people update their systems. It's been like this for at least a week,
as far as I can see, and the emails keep piling up, so it seems
prudent I send a warning about the issue.

As an interim fix, Unit193 very nicely got our usual PPA making
packages for Ubuntu 19.10, which you can use in place of the packages
from Canonical. To activate this, do the following:

$ sudo add-apt-repository ppa:wireguard/wireguard
$ sudo apt-get update
$ sudo apt-get upgrade

That should result in updating your wireguard package from Canonical's
to the working and up to date one inside of the PPA.

Sorry about this. For 20.04 LTS, Canonical will be shipping wireguard
along with their kernel, and we've also discussed them doing the same
for 18.04 LTS. This means that it'll be built as part of their CI and
distributed normally, so problems like this shouldn't come up again.
And of course, with WireGuard being upstream now, as Linux 5.6
trickles down into the distros, this class of problems should
disappear entirely.

Regards,
Jason