Bug#921538: Fails to start since upgrade to 1.9.0-1

[Trout, Diane E.]

> 
> It seems like chroot'ing to /etc/unbound is attempted. To workaround
you
> can try this:
> 
> cat << EOF > /etc/unbound/unbound.conf.d/chroot.conf
> server:
>   chroot: ""
> EOF
> service unbound restart

This fix worked for me.