class Bundler::ParallelInstaller

def worker_pool
  @worker_pool ||= Bundler::Worker.new @size, "Parallel Installer", lambda { |spec_install, worker_num|
    gem_installer = Bundler::GemInstaller.new(
      spec_install.spec, @installer, @standalone, worker_num, @force
    )
    success, message = gem_installer.install_from_spec
    if success && !message.nil?
      spec_install.post_install_message = message
    elsif !success
      spec_install.state = :failed
      spec_install.error = message
    end
    spec_install
  }
end