Ruby on Rails 和 Rake 问题：未初始化的常量 Rake::DSL

Ruby on Rails and Rake problems: uninitialized constant Rake::DSL

提问by HRóDóLFR

I'm having a really frustrating issue: Rakeis being dumb.

我遇到了一个非常令人沮丧的问题：Rake很笨。

Here's how the problem comes about:

以下是问题的产生方式：

$ rails new test_app
$ rails generate scaffold new_scaffold field1:string field2:text

Both of those work just fine, but then when I do this,

这两个工作都很好，但是当我这样做时，

$ rake db:migrate

I get the following error.

我收到以下错误。

(in /home/mikhail/test_app)
rake aborted!
uninitialized constant Rake::DSL
/usr/lib/ruby/1.9.1/rake.rb:2482:in `const_missing'
/usr/lib/ruby/gems/1.9.1/gems/rake-0.9.0/lib/rake/tasklib.rb:8:in `<class:TaskLib>'
/usr/lib/ruby/gems/1.9.1/gems/rake-0.9.0/lib/rake/tasklib.rb:6:in `<module:Rake>'
/usr/lib/ruby/gems/1.9.1/gems/rake-0.9.0/lib/rake/tasklib.rb:3:in `<top (required)>'
/usr/lib/ruby/gems/1.9.1/gems/rake-0.9.0/lib/rake/rdoctask.rb:20:in `require'
/usr/lib/ruby/gems/1.9.1/gems/rake-0.9.0/lib/rake/rdoctask.rb:20:in `<top (required)>'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks/documentation.rake:1:in `require'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks/documentation.rake:1:in `<top (required)>'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks.rb:15:in `load'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks.rb:15:in `block in <top (required)>'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks.rb:6:in `each'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/tasks.rb:6:in `<top (required)>'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:214:in `require'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:214:in `initialize_tasks'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:139:in `load_tasks'
/usr/lib/ruby/gems/1.9.1/gems/railties-3.0.7/lib/rails/application.rb:77:in `method_missing'
/home/mikhail/test_app/Rakefile:7:in `<top (required)>'
/usr/lib/ruby/1.9.1/rake.rb:2373:in `load'
/usr/lib/ruby/1.9.1/rake.rb:2373:in `raw_load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:2007:in `block in load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:2058:in `standard_exception_handling'
/usr/lib/ruby/1.9.1/rake.rb:2006:in `load_rakefile'
/usr/lib/ruby/1.9.1/rake.rb:1991:in `run'
/usr/bin/rake:31:in `<main>'

I've looked about the Internet for similar/same errors, and people have had them. Just no one ever seems to solve the problem!

我在互联网上查看过类似/相同的错误，人们也遇到过这些错误。只是似乎从来没有人解决过这个问题！

How do I fix this problem?

我该如何解决这个问题？

回答by Caley Woods

A tweet from DHHearlier. Rake .9.0 breaks Rails and several other things, you need to:

DHH早些时候的一条推文。Rake .9.0 破坏了 Rails 和其他一些东西，你需要：

gem "rake", "0.8.7"

in your Gemfile.

在你的 Gemfile 中。

回答by Arrumaco

I made some research just after my previous answer (sorry, I must do before it).

我在上一个回答之后做了一些研究（对不起，我必须在它之前做）。

All problems are solved with Rake gem 0.9.2.. I followed these steps:

所有问题都用 Rake gem 0.9.2 解决了。我按照以下步骤操作：

• I installed gem install rake -v=0.9.2(I had the 0.9.1 gem)
• removed the 0.9.1 with gem uninstall rake -v=0.9.1
• updated with bundle update

• then the db:migrateshowed a warning, WARNING: Global access to Rake DSL methods is deprecated. Please....

  It was solved by adding the following to the Rake file.

  module ::YourApplicationName  
    class Application
      include Rake::DSL
    end
  end
  

• I ommited the module ::RakeFileUtils extend Rake::FileUtilsExtendoption sugested by @databyte.

• 我安装了gem install rake -v=0.9.2（我有 0.9.1 gem）
• 删除了 0.9.1 gem uninstall rake -v=0.9.1
• 更新为 bundle update

• 然后db:migrate显示了警告，WARNING: Global access to Rake DSL methods is deprecated. Please....

  它是通过将以下内容添加到 Rake 文件中解决的。

  module ::YourApplicationName  
    class Application
      include Rake::DSL
    end
  end
  

• 我省略了@databyte 建议的module ::RakeFileUtils extend Rake::FileUtilsExtend选项。

It means that the Rake gem 0.9.2 works fine!

这意味着 Rake gem 0.9.2 工作正常！

回答by djblue2009

Going through Chapter 2 of Railstutorial (demo_app) and ran into this problem. I tried all of the other answers listed here, but couldn't get it to work until I did this:

阅读 Railstutorial (demo_app) 的第 2 章并遇到了这个问题。我尝试了此处列出的所有其他答案，但在我这样做之前无法让它发挥作用：

Put this in your Rakefile above require 'rake':

把它放在你的 Rakefile 上面 require 'rake'：

require 'rake/dsl_definition'

via How to fix the uninitialized constant Rake::DSL problem on Heroku?

通过如何修复 Heroku 上未初始化的常量 Rake::DSL 问题？

I also recommitted and pushed all files to Github and Heroku.

我还重新提交并将所有文件推送到 Github 和 Heroku。

回答by Branstar

All I needed to do was use:

我需要做的就是使用：

gem install rake

I had version 0.9.2 already, just needed installing.

我已经有了 0.9.2 版本，只需要安装。

回答by hohner

Reinstall the rake gem and it shouldwork fine:

重新安装 rake gem，它应该可以正常工作：

gem uninstall rake -v=0.9.2 
gem install rake -v=0.9.2

If not, specify version '0.8.7' in your Gemfile.

如果没有，请在您的 Gemfile 中指定版本 '0.8.7'。

回答by Travis Reeder

If not using Bundler:

如果不使用 Bundler：

sudo gem install rake -v 0.8.7
sudo gem uninstall rake

Then choose to uninstall 0.9.0.

然后选择卸载0.9.0。

回答by Jonathon Horsman

If like me you're stuck on rake 0.8.7, and you're using Rails 3.2.x then railties adds a requirement for Rake::DSL

如果像我一样你被困在 rake 0.8.7 上，并且你使用的是 Rails 3.2.x，那么 railties 会增加对 Rake::DSL 的要求

To solve this, to the top of your Rakefile you should add:

要解决这个问题，您应该在 Rakefile 的顶部添加：

module Rake
  module DSL
  end
end

回答by Gaurav Gupta

I solved the same problem with the following steps:

我通过以下步骤解决了同样的问题：

In Gemfile:

在 Gemfile 中：

gem 'rake', '0.9.2'

Then ran this on the console:

然后在控制台上运行：

sudo bundle update rake

Then added the following lines to Rakefile:

然后将以下几行添加到 Rakefile：

require 'rake/dsl_definition'
include Rake::DSL

回答by databyte

Rails 3.1.rc1 has been updated. For your own Rakefiles, you can add this before the call to load_tasks.

Rails 3.1.rc1 已更新。对于您自己的 Rakefile，您可以在调用 load_tasks 之前添加它。

module ::YourApplicationName
  class Application
    include Rake::DSL
  end
end

module ::RakeFileUtils
  extend Rake::FileUtilsExt
end

https://gist.github.com/4cd2bbe68f98f2f0249f

https://gist.github.com/4cd2bbe68f98f2f0249f

UPDATE: Also noticed it's already answered here as well: Undefined method 'task' using Rake 0.9.0

更新：还注意到这里也已经回答了：使用 Rake 0.9.0 的未定义方法“任务”

回答by Paul

I had the same issue and had to use the rake 0.8.7 gem instead of 0.9.0.

我遇到了同样的问题，不得不使用 rake 0.8.7 gem 而不是 0.9.0。