I'm putting this obvious solution up as I couldn't see it anywhere online.
If you try to start up boot2docker with boot2docker start and it returns.
error in run: Failed to start machine "boot2docker-vm": exit status 1
Before destroying everything and wiping your ~/Virtualbox VMs folder, try starting up Virtualbox and seeing if the vm simply hasn't been suspended due to an OSX suspend or shutdown.
- Unpause the machine
- Send a shutdown signal
- Try boot2docker start again.
And that's it, hope it works for you.