'Failed to get device attributes: no such file or directory' is raised by LXD when it cannot create devices for the containers file system. Since LXD does work for you, I suspect Juju is configuring the container/file system wrongly.
'Failed to get device attributes: no such file or directory' is raised by LXD when it cannot create devices for the containers file system. Since LXD does work for you, I suspect Juju is configuring the container/file system wrongly.