# File lib/bundler/installer/parallel_installer.rb, line 86
  def worker_pool
    @worker_pool ||= Bundler::Worker.new @size, lambda { |spec_install, worker_num|
      message = Bundler::GemInstaller.new(
        spec_install.spec, @installer, @standalone, worker_num, @force
      ).install_from_spec
      spec_install.post_install_message = message unless message.nil?
      spec_install
    }
  end