I installed docker on a Debian 7 machine in the following way
$ echo deb http://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list
$
Seems like there are a few ways this can occur. The issue I had was that the docker disk image had hit its maximum size (Docker Whale -> Preferences -> Disk if you want to view what size that is in OSX).
I upped the limit and and was good to go. I'm sure cleaning up unused images would work as well.