未定义的方法`cattr_accessor‘for RailsUpgrade::Upgraders::RouteRedrawer:Class

Question

我正在将一个Rails 2应用程序升级到Rails 3，然后我安装了rails-upgrade gem：

$ gem install rails-upgrade --user-install
Fetching: rails-upgrade-0.0.2.gem (100%)
PostInstall.txt
Successfully installed rails-upgrade-0.0.2
1 gem installed
Installing ri documentation for rails-upgrade-0.0.2...
Installing RDoc documentation for rails-upgrade-0.0.2...

然后我运行了check，但它引发了这个错误：

$ rails-upgrade check
/home/neoriddle/.gem/ruby/1.8/gems/rails-upgrade-0.0.2/lib/rails-upgrade/upgraders/routes.rb:28: undefined method `cattr_accessor' for RailsUpgrade::Upgraders::RouteRedrawer:Class (NoMethodError)
    from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:55:in `gem_original_require'
    from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:55:in `require'
    from /home/neoriddle/.gem/ruby/1.8/gems/rails-upgrade-0.0.2/lib/rails-upgrade.rb:12
    from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:55:in `gem_original_require'
    from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:55:in `require'
    from /home/neoriddle/.gem/ruby/1.8/gems/rails-upgrade-0.0.2/bin/rails-upgrade:7
    from /home/neoriddle/.gem/ruby/1.8/bin/rails-upgrade:19:in `load'
    from /home/neoriddle/.gem/ruby/1.8/bin/rails-upgrade:19

哪里出了问题，我该如何解决它？

我已经安装了Rails 3和所需的所有依赖项：

$ rails -v
Rails 3.0.9
$ ruby -v
ruby 1.8.7 (2011-02-18 patchlevel 334) [i686-linux]
$ gem list active

*** LOCAL GEMS ***

active_scaffold_vho (3.0.20)
activemerchant (1.15.0, 1.14.0)
activemodel (3.0.9, 3.0.7, 3.0.5, 3.0.3)
activerecord (3.0.9, 3.0.7, 3.0.3, 2.3.11, 2.3.5, 2.2.3, 2.1.2, 2.1.1, 2.0.5, 1.15.3)
activeresource (3.0.9, 3.0.7, 3.0.3, 2.3.11, 2.3.5, 2.2.3, 2.1.2, 2.1.1)
activesupport (3.0.9, 3.0.7, 3.0.5, 3.0.3, 2.3.11, 2.3.5, 2.2.3, 2.1.2, 2.1.1, 2.0.5, 1.4.2)
$ gem list action

*** LOCAL GEMS ***

actionmailer (3.0.9, 3.0.7, 3.0.3, 2.3.11, 2.3.5, 2.2.3, 2.1.2, 2.1.1, 1.3.3)
actionpack (3.0.9, 3.0.7, 3.0.3, 2.3.11, 2.3.5, 2.2.3, 2.1.2, 2.1.1, 1.13.3)
actionwebservice (1.2.6, 1.2.3)

如果你需要更多的信息，请找我。

Answer 1

我不认为这个gem已经被更新为与Rails3兼容，唯一的选择就是给自己弄一份Rails 3 Upgrade Handbook的副本，然后用它来完成升级过程。

我在这里写了一篇关于将Rails2应用程序升级到Rails3的博客文章：http://ryanbigg.com/2010/11/the-rails-3-upgrade/。