How to show Vagrant box version used in a particular directory
 I have multiple Vagrant boxes, and would like to see what version of what box is running in which directory.  
 vagrant box list returns a global list of boxes:  
puphpet/centos65-x64   (virtualbox, 1.2.1)
puphpet/centos65-x64   (virtualbox, 2.0)
 vagrant global-status shows directories with providers:  
id       name    provider   state    directory
--------------------------------------------------
a427238  default virtualbox poweroff /path/to/dir1
fa21751  default virtualbox running  /path/to/dir2
But how can I see which Vagrant box version is used in which directory?
 This data is possible to retrieve but is not exposed, as far as I know, through the Vagrant CLI.  Take a look in ~/.vagrant.d/data/machine-index/index for Linux or macOS and I would assume it'd be something like C:Userswhoever.vagrant.ddatamachine-index on Windows.  
You'll get some unformatted JSON which contains details on every machine Vagrant knows about. If you run the JSON through a pretty-printer/beautifier you'll get one of these for every machine:
"d62342a255436211725abe8fd3c313ea": {
    "local_data_path": "/Users/whoever/mymachine/.vagrant",
    "name": "default",
    "provider": "virtualbox",
    "state": "poweroff",
    "vagrantfile_name": null,
    "vagrantfile_path": "/Users/whoever/mymachine",
    "updated_at": null,
    "extra_data": {
        "box": {
            "name": "ubuntu/xenial64",
            "provider": "virtualbox",
            "version": "20170706.0.0"
        }
    }
},
 And the box information associated with your machine is right there.  The ubuntu/xenial64 box on the virtualbox provider version 20170706.0.0 .  
