ruby-on-rails-3 – 在rails动作中启动Watir-Webdriver

下一代码从irb正常工作：

require 'rubygems'
require 'watir-webdriver'
require 'headless'

Headless.ly do
  browser = Watir::Browser.new :firefox
  browser.goto "google.com"
  browser.close
end

如果我尝试从rails应用程序运行它有下一个问题：

的Gemfile：

gem 'headless'
gem 'watir-webdriver'

行动：

def test_action
    Headless.ly do
          browser = Watir::Browser.new(:firefox)
          browser.goto "google.com"
          browser.close
     end
end

有下一个输出：

no such file to load -- {
  "frozen": {
    "app.update.auto": false,"app.update.enabled": false,"browser.download.manager.showWhenStarting": false,"browser.EULA.override": true,"browser.EULA.3.accepted": true,"browser.link.open_external": 2,"browser.link.open_newwindow": 2,"browser.offline": false,"browser.safebrowsing.enabled": false,"browser.safebrowsing.malware.enabled": false,"browser.search.update": false,"browser.sessionstore.resume_from_crash": false,"browser.shell.checkDefaultBrowser": false,"browser.tabs.warnOnClose": false,"browser.tabs.warnOnOpen": false,"devtools.errorconsole.enabled": true,"dom.disable_open_during_load": false,"extensions.autoDisableScopes": 10,"extensions.logging.enabled": true,"extensions.update.enabled": false,"extensions.update.notifyUser": false,"network.manage-offline-status": false,"network.http.phishy-userpass-length": 255,"offline-apps.allow_by_default": true,"prompts.tab_modal.enabled": false,"security.fileuri.origin_policy": 3,"security.fileuri.strict_origin_policy": false,"security.warn_entering_secure": false,"security.warn_entering_secure.show_once": false,"security.warn_entering_weak": false,"security.warn_entering_weak.show_once": false,"security.warn_leaving_secure": false,"security.warn_leaving_secure.show_once": false,"security.warn_submit_insecure": false,"security.warn_viewing_mixed": false,"security.warn_viewing_mixed.show_once": false,"signon.rememberSignons": false,"toolkit.networkmanager.disable": true,"toolkit.telemetry.prompted": 2,"toolkit.telemetry.enabled": false,"toolkit.telemetry.rejected": true
  },"mutable": {
    "browser.dom.window.dump.enabled": true,"browser.startup.page": 0,"browser.startup.homepage": "about:blank","dom.max_script_run_time": 30,"dom.report_all_js_exceptions": true,"javascript.options.showInConsole": true,"network.http.max-connections-per-server": 10,"webdriver_accept_untrusted_certs": true,"webdriver_assume_untrusted_issuer": true
  }
}

哪里有问题？