Comment 7 for bug 1890942

This is related to https://bugs.launchpad.net/cloud-images/+bug/1874453 . We are still investigating the overall route we are taking with serial console connections in cloud images. However, there are workarounds available.

What happened in my test was a timeout on startup, with it hanging for quite a long time. Killing it took a similarly long time. However, adding in any serial file debug sped this up. As a workaround, you can use a change proposed:

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"
  config.vm.provider "virtualbox" do |vb|
    # Set a Null file handler for the serial console
    vb.customize [ "modifyvm", :id, "--uartmode1", "file", File::NULL ]
  end

If you are running into something other than a timeout on startup (and eventually a complete hang of the machine), and adding in a serial bus logger to Null file doesn't solve the issue, please let us know.