I have a MacBook Pro running Yosemite.  On this I have Virtualbox installed with an Ubuntu system running within it.  All packages on both are reasonably up to date (within a month of current).Within that Ubuntu VM I ran the following:$ sudo bash# apt-get install docker.io...# docker versionClient version: 1.0.1Client API version: 1.12Go version (client): go1.2.1Git commit (client): 990021aServer version: 1.0.1Server API version: 1.12Go version (server): go1.2.1Git commit (server): 990021a# docker pull centos...# docker imagesREPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE...centos              latest              88f9454e60dd        8 days ago          210 MB# docker run -it centos /bin/bash2015/03/12 19:59:57 exec format error#This sequence of commands is directly taken from a popular tutorial and a talk based on it at a recent conference.  The only difference between what I did and the tutorial is, I did not install the boot2docker software, rather I just installed docker directly in my pre-existing VM.Why did this command fail, and if my configuration is to blame, what are my options on fixing it?  I prefer not to install boot2docker or other tools on the host system if possible.
exec format error on docker run
executable;docker