Trying to make a GLI app work as an in-process Aruba app

gliip.rb

#!/usr/bin/env ruby
require 'gli'

module FooCommand
  def bootstrap_foo
    desc 'Say sup to some foo'

    arg 'foo arg'
    command :foo do |c|
      c.action do |global_options, options, args|
        @stdout.puts("Sup, #{args.shift}")
      end
    end
  end
end

module MyApp
  class Runner
    include GLI::App
    include FooCommand

    def initialize(argv, stdin=STDIN, stdout=STDOUT, stderr=STDERR, kernel=Kernel)
      @argv, @stdin, @stdout, @stderr, @kernel = argv, stdin, stdout, stderr, kernel
    end

    def execute!
      program_desc 'Describe your application here'
      version '0.0.0'
      subcommand_option_handling :normal
      arguments :strict

      desc 'a global flag'
      flag [:g, :global]

      pre do |global,command,options,args|
        true
      end

      post do |global,command,options,args|
      end

      on_error do |exception|
        true
      end

      bootstrap_foo
      run(@argv)
    end
  end
end

exit MyApp::Runner.new(ARGV).execute!