Since I know this will happen again I want to remind myself and others how to fix it.

I had this error A VirtualBox machine with the name 'homestead' already exists. when doing my normal vagrant up. I got some help at http://stackoverflow.com/questions/26993903/a-virtualbox-machine-with-the-name-homestead-already-exists but it was not made too clear.

Here are the exact steps for me to fix this

Run vboxmanage list vms

This will output a list

"homestead" {5dc30604-8ebe-4060-8966-4881958e6bf5}
"boot2docker-vm" {38af33d4-7ebc-4498-a80e-39711a08b413}
"settler_default_1434987271004_24349_1440846292799_16470" {2c80bf94-99b8-4b51-95a0-034dddae8c33}

Then I took the id of homestead 5dc30604-8ebe-4060-8966-4881958e6bf5 and did

echo '5dc30604-8ebe-4060-8966-4881958e6bf5' > ~/Homestead/.vagrant/machines/default/virtualbox/id

UPDATE

Rough day. Like I said this rarely happens but in this case I also had the default: Warning: Authentication failure. Retrying... error so I did this

cd /tmp
wget https://raw.githubusercontent.com/mitchellh/vagrant/master/keys/vagrant.pub
cat vagrant.pub >> ~/.ssh/authorized_keys