Chunk of VagrantFile that I include the "hack" for -- seemed to address the issue.

VagrantFile

  config.vm.provision :puppet do |puppet|
    puppet.facter = {
      "hack=hack LANG=en_US.UTF-8 hack" => "hack",
      'fqdn'             => "#{config.vm.hostname}",
      'ssh_username'     => "#{ssh_username}",
      'provisioner_type' => ENV['VAGRANT_DEFAULT_PROVIDER'],
    }
    puppet.manifests_path = "#{data['vm']['provision']['puppet']['manifests_path']}"
    puppet.manifest_file  = "#{data['vm']['provision']['puppet']['manifest_file']}"
    puppet.module_path    = "#{data['vm']['provision']['puppet']['module_path']}"

    if !data['vm']['provision']['puppet']['options'].empty?
      puppet.options = data['vm']['provision']['puppet']['options']
    end
  end

This update was actually in puphpet/vagrant/Vagrantfile-local

If you compare with what is shipped, tou can see where I add:
"hack=hack LANG=en_US.UTF-8 hack" => "hack",

That seems to do the trick.

That's the line I was talking about. There is an issue with inconsistent provisioning, though. Seems that sometimes running vagrant provision fails after building the box the first time. On the same spot.