unbound fail after upgrade Ubuntu from 17.10 to 18.04

[Phil Pennock]

On 2018-04-30 at 12:26 -0400, Paul Wouters via Unbound-users wrote:
> On Mon, 30 Apr 2018, Phil Pennock via Unbound-users wrote:
> > You needed Unbound before.  Are you _sure_ you still need it?  It might
> > be that systemd-resolved does what you need now.
> 
> Does systemd-resolved still sends out your query over ALL interfaces'
> DNS servers and trusts the FIRST answer that comes back regardless of
> DNSSEC status?

Pass: it lacked the configurability I needed to be a viable option for
the deployment where I was looking.  EC2 instance, needs access to
resolve "internal." and "amazonaws.com." using the in-VPC
Amazon-provided DNS resolvers, for customized results, but resolving
everything else via direct resolution, because Amazon's resolvers break
DNSSEC.

So I had a solid basis for sticking with Unbound, so that I could get
validation for everything except the domains which _have_ to be passed
onto certain upstreams.  Cue much cussing yesterday.  On the bright
side, I got a debugged setup in time to share details to help someone
else.

-Phil