title: Issue when trying to start minikube with virtualbox?
body: <p>I'm using the new version of MacOs Catalina, i just installed Docker, Minikube and Virtualbox. All these from Homebrew. When i try to start <code>minikube start</code>, i get following error:</p>
  
  <pre><code>  minikube v1.9.2 on Darwin 10.15.4
  ✨  Using the virtualbox driver based on user configuration
    Starting control plane node m01 in cluster minikube
    Creating virtualbox VM (CPUs=2, Memory=6000MB, Disk=20000MB) ...
  ❗  This VM is having trouble accessing https://k8s.gcr.io
    To pull new external images, you may need to configure a proxy: 
  https://minikube.sigs.k8s.io/docs/reference/networking/proxy/
  
    Failed to enable container runtime: enable docker.: NewSession: write tcp 
  127.0.0.1:50207-&gt;127.0.0.1:50185: write: broken pipe
  
    minikube is exiting due to an error. If the above message is not useful, open an issue:
    https://github.com/kubernetes/minikube/issues/new/choose
  </code></pre>
  
  <p>With <code>hyperkit-vm</code> its working fine, but not with virtualbox?
  Anyone know why I am getting this problem? I did not get this error for few days ago, suddenly i get this now?</p>
  
  <p>Thank for the help!</p>