How to debug “Vagrant cannot forward the specified ports on this VM” message

Question

I\'m trying to start a Vagrant instance and getting the following message:

Vagrant cannot forward the specified ports on this VM, since they
would collide wi         


        

Answer 1

My observation: I did not have any processes running on port 8000, so essentially the port forwarding did not work. Fix: Phil's answer provided a solution

~/.vagrant.d/boxes/ 

The above path had other versions of vagrant files that listed the port 8000. Once I pruned them all using the below command I was able to run vagrant up successfully

vagrant box remove [name] --all