class Bundler::Installer

def index
  @index ||= begin
    index = Index.new
    if File.directory?("#{root}/vendor/cache")
      index = cache_source.specs.merge(index).freeze
    end
    rg_sources = sources.select { |s| s.is_a?(Source::Rubygems) }
    other_sources = sources.select { |s| !s.is_a?(Source::Rubygems)   }
    other_sources.each do |source|
      i = source.specs
      Bundler.ui.debug "Source: Processing index"
      index = i.merge(index).freeze
    end
    index = Index.from_installed_gems.merge(index)
    rg_sources.each do |source|
      i = source.specs
      Bundler.ui.debug "Source: Processing index"
      index = i.merge(index).freeze
    end
    index
  end
end