如何确认Devkit是否安装成功

昨天在安装了Ruby 1.9.2 ，并且将其路径加入到Devkit的config.yml中，并且使用ruby dk.rb install安装（不幸的是，没注意安装信息）。。但是依然无法构建native gem。于是重装Ruby，按照devkit的安装说明来安装。还是不正确。 Devkit的安装说明的第4步为Run Installation Scripts：

• cd <DEVKIT_INSTALL_DIR> from Step 3 above.
• ruby dk.rb init to generate the config.yml file to be used later in this Step. Your installed Rubies will be listed there (only those installed by a RubyInstaller package are detected at present).
• edit the generated config.yml file to include installed Rubies not automagically discovered or remove Rubies you do not want to use the DevKit with.
• [optional] ruby dk.rb review to review the list of Rubies to be enhanced to use the DevKit and verify the changes you made to it are correct.
• finally, ruby dk.rb install to DevKit enhance your installed Rubies. This step installs (or updates) an operating_system.rb file into the relevant directory needed to implement a RubyGems pre_install hook and a devkit.rb helper library file into <RUBY_INSTALL_DIR>\lib\ruby\site_ruby. NOTE: you may need to use the --force option to update (with backup of the originals) the above mentioned files as discussed at the SFX DevKit upgrade FAQ entry.

在最后一步可知，安装Devkit其实就是更新了operating_system.rb文件，同时新建了devkit.rb文件。 在我的电脑上devkit.rb已经创建好（Devkit安装在D:/Ruby187/devkit目录下，其他电脑上的路径可能与我的不同）：

# enable RubyInstaller DevKit usage as a vendorable helper library
unless ENV['PATH'].include?('d:\\Ruby187\\devkit\\mingw\\bin') then
  puts 'Temporarily enhancing PATH to include DevKit...'
  ENV['PATH'] = 'd:\\Ruby187\\devkit\\bin;d:\\Ruby187\\devkit\\mingw\\bin;' + ENV['PATH']
end

# enable RubyInstaller DevKit usage as a vendorable helper library
unless ENV['PATH'].include?('d:\\Ruby187\\devkit\\mingw\\bin') then
  puts 'Temporarily enhancing PATH to include DevKit...'
  ENV['PATH'] = 'd:\\Ruby187\\devkit\\bin;d:\\Ruby187\\devkit\\mingw\\bin;' + ENV['PATH']
end

在Ruby1.9.2中，有两个operating_system.rb文件，分别位于lib\ruby\site_ruby\1.9.1\rubygems\defaults和lib\ruby\1.9.1\rubygems\defaults下，其内容相同：

# :DK-BEG: missing DevKit/build tool convenience notice

Gem.pre_install do |gem_installer|
  unless gem_installer.spec.extensions.empty?
    have_tools = %w{gcc make sh}.all? do |t|
      system("#{t} --version > NUL 2>&1")
    end

    unless have_tools
      raise Gem::InstallError,<<-EOT
The '#{gem_installer.spec.name}' native gem requires installed build tools.

Please update your PATH to include build tools or download the DevKit
from 'http://rubyinstaller.org/downloads'and follow the instructions
at 'http://github.com/oneclick/rubyinstaller/wiki/Development-Kit'
EOT
    end
  end
end
# :DK-END:

# :DK-BEG: missing DevKit/build tool convenience notice

Gem.pre_install do |gem_installer|
  unless gem_installer.spec.extensions.empty?
    have_tools = %w{gcc make sh}.all? do |t|
      system("#{t} --version > NUL 2>&1")
    end

    unless have_tools
      raise Gem::InstallError,<<-EOT
The '#{gem_installer.spec.name}' native gem requires installed build tools.

Please update your PATH to include build tools or download the DevKit
from 'http://rubyinstaller.org/downloads' and follow the instructions
at 'http://github.com/oneclick/rubyinstaller/wiki/Development-Kit'
EOT
    end
  end
end
# :DK-END:

参考了我电脑上其他版本的Ruby（1.8.7-p334和1.8.7-p330，分别都只有一个operating_system.rb），在安装好Devkit之后，该文件应该为：

Gem.pre_install do |i|
  unless ENV['PATH'].include?('d:\\Ruby187\\devkit\\mingw\\bin') then
    puts 'Temporarily enhancing PATH to include DevKit...'
    ENV['PATH'] = 'd:\\Ruby187\\devkit\\bin;d:\\Ruby187\\devkit\\mingw\\bin;' + ENV['PATH']
  end
end

Gem.pre_install do |i|
  unless ENV['PATH'].include?('d:\\Ruby187\\devkit\\mingw\\bin') then
    puts 'Temporarily enhancing PATH to include DevKit...'
    ENV['PATH'] = 'd:\\Ruby187\\devkit\\bin;d:\\Ruby187\\devkit\\mingw\\bin;' + ENV['PATH']
  end
end

在修改了lib\ruby\1.9.1\rubygems\defaults\operating_system.rb之后，构建native gem时，依然找不到Devkit；但修改lib\ruby\site_ruby\1.9.1\rubygems\defaults\operating_system.rb 后（不修改lib\ruby\1.9.1\rubygems\defaults\operating_system.rb），便可以成功构建。 所以，如何确认Devkit是否安装成功呢？ 答：检查devkit.rb和operating_system.rb 文件，其内容应该和上面的内容相同；否则，安装不成功。 可以手动更改这两个文件为上面的形式（好像也可以删除这两个文件，然后使用ruby dk.rb install命令，此时会创建 – 未验证）。在使用ruby dk.rb install时候，需要注意安装信息或警告，如果某些文件已经存在，可能会跳过。 但是，为什么在看似“正常”的安装步骤下，为什么没能安装好Devkit？ 我没有找到原因；或许我的某个步骤有问题。我发现，虽然我安装的是1.9.2，但是却被安装在了lib\ruby\1.9.1目录下，官方解释说：

This version is a “library compatible version.” Ruby 1.9.2 is almost 1.9.1 compatible, so the library is installed in the 1.9.1 directory.