I recently had the same issue. Tried different configurations in the Vagrantfile but they didn't work.

I just downgraded the VirtualBox version. I was using VirtualBox-6.0.14-133895-OSX and I installed the VirtualBox-5.2.14-123301-OSX version (as the previous ones threw a "The system extension “VBoxDrv.kext” is not compatible" error as I'm using Mojave 10.14.5).

No special configuration in the Vagrantfile was needed.

I had the same issues before in some other projects. disco64 seems to have some problems with vagrant + virtualbox 6.0

I submitted a bug report to cloud images: https://bugs.launchpad.net/cloud-images/+bug/1857325

I am not sure if you are still facing this issue, @neoplomero, but have you inspected the progress of the VM in VirtualBox?

In my case, after some setup, the VM prompted me for login credentials (screenshot below):

Entering the following credentials completed the task successfully
Username: vagrant
Password: vagrant

Also, in my case, even after a timeout in the host terminal, my VM setup would continue. Executing vagrant up again after timeout worked.

This happens to me too
host: Ubuntu 18.04, Virtualbox 6.1
Downgrading to Virtualbox 5.2 that comes with Ubuntu software center solve the problem

I do not know what can be done here, seems a generic problem. Perhaps test other distros?

I found a temporary fix in this thread: https://bugs.launchpad.net/cloud-images/+bug/1874453

config.vm.provider 'virtualbox' do |v|
  v.memory = ENV.fetch('RAILS_DEV_BOX_RAM', 2048).to_i
  v.cpus   = ENV.fetch('RAILS_DEV_BOX_CPUS', 2).to_i
  v.customize [ "modifyvm", :id, "--uartmode1", "file", File::NULL ] # add this line to to your Vagrantfile
end

You might also consider to turn on the Virtualbox GUI to see where vagrant up gets stuck by adding another line to your Vagrantfile:

config.vm.provider 'virtualbox' do |v|
  v.memory = ENV.fetch('RAILS_DEV_BOX_RAM', 2048).to_i
  v.cpus   = ENV.fetch('RAILS_DEV_BOX_CPUS', 2).to_i
  v.gui = true # add this line to your Vagrantfile to see what's going on
  v.customize [ "modifyvm", :id, "--uartmode1", "file", File::NULL ]
end

On my host, I'm running macOS 10.15.6, Virtualbox 6.1

Hi, this happened to me too.
host: Mac OS Mojave 10.14.6, Virtualbox 6.0

I tried the temporary fix with
v.customize [ "modifyvm", :id, "--uartmode1", "file", File::NULL ]
and it worked. (Thank you, drssdinblck!

Downgrading to Virtualbox 5.2 worked, too.

I searched similar problems(hashicorp/vagrant#10578 (comment)) and found that it seemed like generic problem of Virtualbox 6.1~.

I couldn't find a solution to the root of this problem by fixing rails-dev-box repo...