gistfile1.txt

  foss-puppet-master:
    provider:
      type: virtualbox
      customize:
        - [modifyvm, !ruby/sym id, '--memory', 6144]
    provisioners:
      - type: hosts
        add_localhost_hostnames: false
        sync_hosts: true
      - type: shell
        path: files/setup.sh
        args: [ !ruby/sym current_branch ]
        keep_color: false

gistfile2.txt

walterheck@walter-envy:~/source/opstheater/deploy/vagrant-oscar$ vagrant up foss-master
 WARN config_builder: The provider attribute, set on vm foss-master, is deprecated and will be removed in an upcoming release. Use the providers attribute instead.
Bringing machine 'foss-master' up with 'virtualbox' provider...
There are errors in the configuration of this machine. Please fix
the following errors and try again:

shell provisioner:
* Shell provisioner `args` must be a string or array.