ruby-on-rails – 规格本地传递,但Travis CI失败

1) User Registration User signs up with valid credentials
     Failure/Error: fill_in 'Username',with: 'dannnnneh'
     Capybara::ElementNotFound:
       Unable to find field "Username"
     # ./spec/features/registrations_controller_spec.rb:8:in `block (2 levels) in <top (required)>'

我在common build problems for Travis CI上阅读使用Capybara.default_wait_time = 15;但是,我或者把它放在错误的地方,否则就不行.

示例说明：

scenario 'User signs up with valid credentials' do
    Capybara.default_wait_time = 15
    visit '/users/sign_up'
    fill_in 'Username',with: 'dannnnneh'
    ...

编辑：

我也试过把capybara.default_wait_time = 15放在rails_helper.rb,spec_helper.rb,spec / support / capybara.rb中.

由于this SO问题,我还将以下内容添加到.travis.yml中.

script:
    - xvfb-run bundle exec rspec spec/features/*.rb

但是,这也不行.

有人知道这个问题可能是什么,还是怎么解决呢？

编辑：

这是我的spec_helper.rb：

require 'simplecov'
SimpleCov.start


require 'capybara'
require 'capybara/poltergeist'

Capybara.javascript_driver = :poltergeist
Capybara.register_driver :poltergeist do |app|
  Capybara::Poltergeist::Driver.new(app,timeout: 15)
end

RSpec.configure do |config|

  config.expect_with :rspec do |expectations|
    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
  end

  config.mock_with :rspec do |mocks|
    mocks.verify_partial_doubles = true
  end

end