How to fix “error in run: Failed to get machine “boot2docker-vm”: machine does not exist”?

In the end, I removed the boot2docker-vm virtual machine:

snowch$ rm -rfi ~/VirtualBox\ VMs/boot2docker-vm/

Original source of the answer: https://github.com/boot2docker/boot2docker/issues/436

Note: this method is probably the quickest but you will lose your existing boot2docker virtual machine. If you want to keep your existing boot2docker virtual machine, you could try Patrick Henning’s answer