安装Rails_Admin时出现问题

如何解决安装Rails_Admin时出现问题

| 我最初在我的gemfile中添加了ѭ0but，但是出现了以下错误：

Bundler could not find compatible versions for gem \"rails\":
  In snapshot (Gemfile.lock):
    rails (3.0.4)

  In Gemfile:
    rails_admin depends on
      rails (~> 3.0.7)

所以我更新到Rails 3.0.7并安装了

rails_admin (0.0.1) from git://github.com/sferik/rails_admin.git (at master)

我在控制台中运行

rake rails_admin:install

，出现此错误：

rake aborted!
undefined method `task\'

这是完整的跟踪：

/Library/Ruby/Gems/1.8/gems/railties-3.0.7/lib/rails/application.rb:215:in `initialize_tasks\'
/Library/Ruby/Gems/1.8/gems/railties-3.0.7/lib/rails/application.rb:139:in `load_tasks\'
/Library/Ruby/Gems/1.8/gems/railties-3.0.7/lib/rails/application.rb:77:in `send\'
/Library/Ruby/Gems/1.8/gems/railties-3.0.7/lib/rails/application.rb:77:in `method_missing\'
/rubyprograms/dreamstill/Rakefile:7
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/rake_module.rb:25:in `load\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/rake_module.rb:25:in `load_rakefile\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:495:in  `raw_load_rakefile\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:78:in `load_rakefile\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:129:in `standard_exception_handling\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:77:in `load_rakefile\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:61:in `run\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:129:in `standard_exception_handling\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/lib/rake/application.rb:59:in `run\'
/Library/Ruby/Gems/1.8/gems/rake-0.9.0/bin/rake:31
/usr/bin/rake:19:in `load\'
/usr/bin/rake:19

怎么回事，如何安装rails_admin？     

解决方法

        这是rake 0.9的已知问题。要解决此问题，只需执行以下操作： 卸载rake 0.9：

gem uninstall rake -v 0.9

将此添加到您的gemfile：

gem \'rake\',\'~> 0.8.7

更新套装：

bundle update

而且您应该很好。