耙子流产了！ nil的未定义方法“先决条件”：NilClass

剧透：它是rspec-railsgem的过时版本！

在将我的sqlite3 gem移动到开发块然后运行’rake db：migrate’以确保一切仍然有效之后，我从rails项目目录发出的任何rake命令都遇到了这个错误。 Rake在我的系统上的其他地方工作正常。 但是我在该目录中运行的任何rake任务都为我提供了跟踪的以下输出：

 /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rspec-rails-2.0.0.beta.18/lib/rspec/rails/tasks/rspec.rake:3:in `' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rspec-rails-2.0.0.beta.18/lib/rspec-rails.rb:8:in `load' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rspec-rails-2.0.0.beta.18/lib/rspec-rails.rb:8:in `block in ' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/railtie.rb:183:in `call' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/railtie.rb:183:in `block in load_tasks' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/railtie.rb:183:in `each' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/railtie.rb:183:in `load_tasks' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/engine.rb:396:in `block in load_tasks' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/application/railties.rb:8:in `each' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/application/railties.rb:8:in `all' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/engine.rb:396:in `load_tasks' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/application.rb:103:in `load_tasks' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/railties-3.1.3/lib/rails/railtie/configurable.rb:30:in `method_missing' /Users/ianyoung/rails/third_app/Rakefile:7:in `' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/rake_module.rb:25:in `load_rakefile' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:501:in `raw_load_rakefile' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:82:in `block in load_rakefile' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:81:in `load_rakefile' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:65:in `block in run' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/bin/rake:33:in `' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `load' /Users/ianyoung/.rvm/gems/ruby-1.9.2-p290/bin/rake:19:in `' 

我得到的第一个错误是问题标题：rake aborted！ nil的未定义方法“先决条件”：NilClass

我也得到了这个，但它并没有给我带来麻烦。 也许它是相关的？：

弃用警告：不推荐使用Rails :: Railtie中的config.generators。 请改用config.app_generators。 （从/Users/ianyoung/rails/third_app/config/application.rb:13调用）DEPRECATION警告：不推荐使用Rails :: Railtie中的config.generators。 请改用config.app_generators。 （来自/Users/ianyoung/rails/third_app/config/application.rb:13）

Answer 1

更新到最新的rspec-rails gem让我解除了这个问题以及弃用警告。

安装最新的webrat gem解决了缺少的has_selector？ 我出于某种原因认为的方法问题比我过时的rspec-rails gem更邪恶。 一切都很好。

感谢您提供的有用评论。