rspec核心Ruby on Rails

您好，我正在用rspec测试我的应用程序：

这是测试文件。

require 'spec_helper'

describe RecipesController do
    render_views
    describe "index" do
        before do
            Recipe.create!(name: "Spaghetti alla Carbonara")
            Recipe.create!(name: "Spaghetti alle vongole e cozze")
            Recipe.create!(name: "Bistecca")
            Recipe.create!(name: "Fritto")

            xhr :get, :index, format: :json, keywords: keywords
        end

        subject(:results) { JSON.parse(response.body) }

        def extract_name 
            ->(object){ object["name"] } 
        end

        context 'quando la ricerca riporta dei risultati' do
            let(:keywords) { 'Spaghetti' }
            it 'essere 200' do
                expect(response.status).to eq(200)
            end

            it 'deve ritornare due risultati' do
                expect(results.size).to eq(2)
            end

            it 'deve esserci la ricetta Spaghetti alla Carbonara' do
                expect(results.map(&extract_name)).to include('Spaghetti alla Carbonara')
            end

            it 'deve esserci la ricetta Spaghetti alle vongole e cozze ' do
                expect(results.map(&extract_name)).to include('Spaghetti alle vongole e cozze')
            end
        end

        context 'quando la ricerca non riporta alcun risulato' do
            let(:keywords) { 'tortellini' }
            it 'non deve ritornare alcun risulato' do
                expect(results.size).to eq(0)
            end
        end


    end
end

当我尝试通过命令启动测试时：

耙db：migrate RAILS_ENV = test; rspec规范/控制器/recipes_controller_spec.rb

我收到这个错误

/var/lib/gems/2.1.0/gems/bundler-1.10.1/lib/bundler/runtime.rb:34：将block in setup': You have already activated rspec-core 3.3.1, but your Gemfile requires rspec-core 2.99.2. Prependingexec捆绑到您的命令中可以解决此问题。（Gem :: LoadError）

如日志中所述，该错误与rspec-core v3.3.1有一些冲突，因此在我的gem文件中，我添加了以下行以安装rspec-core v2.99.2

gem 'rspec-core', '~> 2.99.2'

但是，如果我再次启动该命令（在安装捆绑软件之后并使用捆绑软件exec），结果是相同的。有人有类似的问题吗？