結論
その1
$ vagrant global-status --prune
その2
$ sudo rm -r .vagrant/
経緯
仮想マシンを destroy
しようとするとこんな不吉な赤いメッセージがでてどうにもならなくなる場合があります。
Vagrant was unable to find the OpenStack instance used for your vagrant machine. This can happen when the instance has been deleted via OpenStack APIs or OpenStack Dashboard instead of using vagrant commands. We recommend using the command `vagrant openstack reset` to reset vagrant to a clear state