1：ubuntu 各文件已是最新。 2：搜了其他解决办法，清空 rvm(remove all)，重新安装 ruby，建 gemset，然后 bundle update/install，还是不行。 3：bundle exec rspec spec/ -->出现一个红色 F 错误，后面“段错误（核心已转储）“ 4：bundle exec rspec spec/requests/user_pages_spec.rb -->测试通过 5：bundle exec rspec spec/requests/authentication_pages_spec.rb，分别出现Control frame information、C level backtrace information、Other runtime information、Process memory map 这几大块错误信息，总共 n 多行。 6：应用运行无错。

tiger@tigerPC:~/sample_app$ bundle exec rspec spec/
No DRb server is running. Running in local process instead ...
........[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
..............................................F段错误 (核心已转储)
tiger@tigerPC:~/sample_app$ bundle exec rspec spec/requests/user_pages_spec.rb
No DRb server is running. Running in local process instead ...
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
..................

Finished in 1.45 seconds
18 examples, 0 failures

Randomized with seed 43555

tiger@tigerPC:~/sample_app$ bundle exec rspec spec/requests/authentication_pages_spec.rb
No DRb server is running. Running in local process instead ...
[deprecated] I18n.enforce_available_locales will default to true in the future. If you really want to skip validation of your locale you can set I18n.enforce_available_locales = false to avoid this message.
........../home/tiger/.rvm/rubies/ruby-2.0.0-p576/lib/ruby/gems/2.0.0/gems/rspec-core-2.13.1/lib/rspec/core/example.rb:179: [BUG] vm_call_cfunc - cfp consistency error
ruby 2.0.0p576 (2014-09-19 revision 47628) [x86_64-linux]

-- Control frame information ------------------

Gemfile 如下：

source 'https://rubygems.org'
ruby '2.0.0'
gem 'rails', '4.0.0'
gem 'bootstrap-sass', '2.3.2.0'

group :development, :test do
  gem 'sqlite3', '1.3.7'
  gem 'rspec-rails', '2.13.1'
  gem 'guard-rspec', '2.5.0'
  gem 'spork-rails', github: 'railstutorial/spork-rails'
  gem 'guard-spork', '1.5.0'
  gem 'childprocess', '0.5.3'
end

group :test do
  gem 'selenium-webdriver', '~>2.35.1'
  gem 'capybara', '2.1.0'
  gem 'factory_girl_rails', '4.2.1'
end

gem 'sass-rails', '4.0.3'

gem 'uglifier', '2.1.1'

gem 'coffee-rails', '4.0.0'

gem 'therubyracer', platforms: :ruby

gem 'jquery-rails', '2.2.1'

gem 'turbolinks', '1.1.1'

gem 'jbuilder', '1.0.2'

group :doc do

  gem 'sdoc', '0.3.20', require: false
end

gem 'bcrypt-ruby', '3.0.1'

authentication_pages_spec.rb 如下：

require 'spec_helper'

describe "AuthenticationPages" do
  subject { page }

  describe "signin page" do
    before { visit signin_path }
    it { should have_content('Sign in') }
    it { should have_title('Sign in') }
  end

  describe "signin" do
    before { visit signin_path }

    describe "invalid" do
      before { click_button "Sign in" }

      it { should have_title("Sign in") }
      it { should have_selector("div.alert.alert-error"), text: "invalid" }

      describe "after visiting another page" do
        before { click_link "Home" }
        it { should_not have_selector('div.alert.alert-error') }
      end
    end

    describe "valid" do
      let(:user) { FactoryGirl.create(:user) }
      before do
        fill_in "Email", with: user.email.upcase
        fill_in "Password", with: user.password
        click_button "Sign in"
      end

      it { should have_title(user.name) }
      it { should have_link('Profile', href: user_path(user)) }
      it { should have_link('Sign out'), href: signout_path }
      it { should_not have_link('Sign in'), href: signin_path }

      describe "after signouting" do

        before { click_link 'Sign out' }
        it { should have_link('Sign in') }

      end

    end

  end

  describe "with valid information" do
    let(:user) { FactoryGirl.create(:user) }
    before { sign_in user }

    it { should have_link("Profile", href: user_path(user)) }
    it { should have_link("Settings", href: edit_user_path(user)) }
    it { should have_link("Sign out", href: signout_path) }
    it { should have_title(user.name) }

    it { should_not have_link("Sign in", href: signin_path) }
  end

  describe "访问权限控制" do
    describe "对于未登录的用户" do
      let(:user) { FactoryGirl.create(:user) }

      describe "试图访问编辑页面时" do
        before do
          visit edit_user_path(user)
          fill_in "Email", with: user.email
          fill_in "Password", with: user.password
          click_button "Sign in"
        end

        describe "在登录后" do
          it "应该转向之前用户想访问的页面" do
            expect(page).to have_title("Edit user")
          end
        end
      end

      describe "在users控制器" do
        describe "访问编辑页面" do
          before { visit edit_user_path(user) }

          it { should have_title("Sign in") }
        end

        describe "点击更新按钮" do
          before { patch user_path(user) }
          it "应该跳到登录界面" do
            expect(response).to redirect_to(signin_path)
          end
        end

      end
    end

    describe "试图更改其他用户的资料" do
      let(:user) { FactoryGirl.create(user) }
      let(:wrong_user) {FactoryGirl.create(:user, email: "[email protected]")}
      before { sign_in user, no_capybara: true }

      describe "访问users#edit page" do
        before { visit edit_user_path(wrong_user) }
        it { should_not have_title(full_title("Edit user")) }
      end

      describe "提交一个patch请求给users#update" do
        before { patch user_path(wrong_user) }
        specify { expect(response).to redirect_to(root_path) }
      end
    end

  end
end