Comment 4 for bug 1574969

This is breaking the ability to use vagrant with LXC boxes.

/opt/vagrant/embedded/gems/gems/vagrant-1.8.1/lib/vagrant/batch_action.rb:82:in `block (2 levels) in run'
 INFO interface: error: There was an error executing ["sudo", "/usr/bin/env", "lxc-create", "-B", "best", "--template", "/home/quanah/.vagrant.d/gems/gems/vagrant-lxc-1.2.1/scripts/lxc-template", "--name", "u1690_default_1462660055308_76102", "--", "--tarball", "/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/rootfs.tar.gz", "--config", "/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/lxc-config"]

For more information on the failure, enable detailed logging by setting
the environment variable VAGRANT_LOG to DEBUG.
There was an error executing ["sudo", "/usr/bin/env", "lxc-create", "-B", "best", "--template", "/home/quanah/.vagrant.d/gems/gems/vagrant-lxc-1.2.1/scripts/lxc-template", "--name", "u1690_default_1462660055308_76102", "--", "--tarball", "/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/rootfs.tar.gz", "--config", "/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/lxc-config"]

For more information on the failure, enable detailed logging by setting
the environment variable VAGRANT_LOG to DEBUG.
 INFO interface: Machine: error-exit ["Vagrant::LXC::Errors::ExecuteError", "There was an error executing [\"sudo\", \"/usr/bin/env\", \"lxc-create\", \"-B\", \"best\", \"--template\", \"/home/quanah/.vagrant.d/gems/gems/vagrant-lxc-1.2.1/scripts/lxc-template\", \"--name\", \"u1690_default_1462660055308_76102\", \"--\", \"--tarball\", \"/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/rootfs.tar.gz\", \"--config\", \"/home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/lxc-config\"]\n\nFor more information on the failure, enable detailed logging by setting\nthe environment variable VAGRANT_LOG to DEBUG."]
quanah@ub16:~/vagrant/u1690$ sudo su -
root@ub16:~# lxc-create -B best --template /home/quanah/.vagrant.d/gems/gems/vagrant-lxc-1.2.1/scripts/lxc-template --name u1690_default_1462660055308_76102 -- --tarball /home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/rootfs.tar.gz --config /home/quanah/.vagrant.d/boxes/developerinlondon-VAGRANTSLASH-lxc-xenial/0.1/lxc/lxc-config
best is not a valid backing storage type.