Undefined method 'task' using Rake 0.9.0

I just updated Rake to the latest version (0.9.0.beta.4) and the rake command ends up with the following error message:

rake aborted!
undefined method `task' for #<Anelis::Application:0x9223b6c>

Here is the trace:

undefined method `task' for #<Anelis::Application:0x97ef80c>
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:214:in `initialize_tasks'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:139:in `load_tasks'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/railties-3.0.3/lib/rails/application.rb:77:in `method_missing'
/home/amokrane/Documents/prog/web/learning_rails/anelis/Rakefile:7:in `load_string'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/environment.rb:28:in `eval'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/environment.rb:28:in `load_string'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/environment.rb:16:in `load_rakefile'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:495:in `raw_load_rakefile'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:78:in `block in load_rakefile'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:129:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:77:in `load_rakefile'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:61:in `block in run'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:129:in `standard_exception_handling'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/lib/rake/application.rb:59:in `run'
/usr/local/rvm/gems/ruby-1.9.2-p136/gems/rake-0.9.0.beta.4/bin/rake:31:in `<top (required)>'
/usr/local/rvm/gems/ruby-1.9.2-p136/bin/rake:19:in `load'
/usr/local/rvm/gems/ruby-1.9.2-p136/bin/rake:19:in `<main>'

Anyone experienced the same issue? What could possibly be wrong? Note that I am running Rails 3.0.3, you may also be interested in the content of my Gemfile:

source 'http://rubygems.org'
gem 'rails', '3.0.3'
gem 'sqlite3-ruby', :require => 'sqlite3'
gem 'mysql2'
gem 'legacy_data'
gem 'resources_controller', :git => 'git://github.com/ianwhite/resources_controller'
gem 'will_paginate', '3.0.pre' # pagination
gem 'jquery-rails', '>= 0.2.6'
gem "rmagick" # sudo aptitude install libmagick9-dev
gem "paperclip", "~> 2.3"
gem "nested_form", :git => "git://github.com/madebydna/nested_form.git"
gem "meta_search"
gem "hirb"
gem "devise"
gem "rails_admin", :git => "git://github.com/sferik/rails_admin.git"

How can I fix this problem?

As explained in mordaroso's answer, there is a problem in Rake 0.9.0. You need to temporarily downgrade Rake in order to avoid it:

1. run: gem uninstall rake -v 0.9 (add sudo unless you use rvm)

2. add to your Gemfile: gem 'rake', '~> 0.8.7'

3. and then run: bundle update

You can skip the first step, but then you have to run rake using bundle exec, for example:

bundle exec rake db:migrate

Otherwise you get the following error.

rake aborted!
You have already activated rake 0.9.0, but your Gemfile requires rake 0.8.7. Consider using bundle exec.

###Update

As Alex Chaffee noticed in a comment for Pablo Cantero's answer, that you might need to do the following to uninstall Rake if you still see the problem

rvm use @global && gem uninstall rake -v 0.9.0
rvm use @       && gem uninstall rake -v 0.9.0

Also try the solution suggested in Duke's answer.

I had the same exception when running the 0.9.0.beta.4 version of Rake. It looks like the new Rake::DSL is not loaded properly.

So I added following code to my Rakefile:

require 'rake'

# Rake Fix Code start
# NOTE: change 'Anelis' to your app's module name (see config/application.rb)
module ::Anelis
  class Application
    include Rake::DSL
  end
end

module ::RakeFileUtils
  extend Rake::FileUtilsExt
end
# Rake Fix Code end

MyApp::Application.load_tasks

That way I was able to run my Rake tasks again.

I know that this is not a elegant solution. But if you have to use the --pre version of Rake it might be all right to use this quick hack.

Note: This was just fixed in Rails 3.0.8

The new version of Rake does not put its DSL commands (task, file, desc, import, etc.) in the root of the Object namespace anymore (placing them in Object meant every object has a task command, not very nice. The DSL commands are available by mixing in the Rake::DSL module into any module needing the commands.

Until Ruby on Rails is updated to work with Rake 0.9.x, put the following in your project Rakefile after "require rake" and before the call to Application.load_tasks:

class Rails::Application
  include Rake::DSL if defined?(Rake::DSL)
end

I've created an issue for rails_admin about this same error.

The answer:

> This is a general Rails problem: http://twitter.com/dhh/status/71966528744071169 > > There should be a 3.0.8 release soon that fixes it. In the mean time, you can add the following line to your Gemfile: > > gem 'rake', '~> 0.8.7'

It's a problem in Rake (0.9.0), it was announced by DHH on Twitter.

> Rake 0.9, which was released yesterday, broke Rails (and others). While we wait for a fix, you'll want gem 'rake', '0.8.7' in your Gemfile.

This has been fixed in Ruby on Rails 3.0.8.rc1 which should be released in a few days time.

Rake 0.9.1 has just been released which reverses the change that caused this error but adds a deprecation warning: https://github.com/jimweirich/rake/commit/44aec3ceac085740bce0c385bccd65fc4d1d911c

I use rvm, but uninstalling doesn't help me. So I manually remove all 0.9 files from .rvm/gems/ruby@global directory and everything becomes as before!

without the need to uninstall Rake 0.9.x, add

> gem 'rake', '~> 0.8.7'

to your Gemfile and just type

> bundle exec rake -T