vagrant-nesed-virtualbox

# ref
# https://computingforgeeks.com/how-to-install-virtualbox-on-fedora-linux/
# tweak below for Mac OS X
# https://stefanwrobel.com/how-to-make-vagrant-performance-not-suck

# vagrantfile
```shell
testbox_script = <<-SHELL
    #!/bin/bash
    set -euxo pipefail

    SHELL

Vagrant.configure("2") do |config|
    config.vm.box = "generic/ubuntu2004"
    config.vm.hostname = "testbox"
    config.vm.provider "virtualbox" do |vb|
      vb.customize ['modifyvm', :id, '--nested-hw-virt', 'on']
      vb.memory = "4096"
      vb.cpus = "4"
    end

    args = []
    config.vm.provision "shell", inline: testbox_script
end
```