# File lib/bundler/source/rubygems.rb, line 362
      def cached_specs
        @cached_specs ||= begin
          idx = installed_specs.dup

          Dir["#{cache_path}/*.gem"].each do |gemfile|
            next if gemfile =~ /^bundler\-[\d\.]+?\.gem/
            s ||= Bundler.rubygems.spec_from_gem(gemfile)
            s.source = self
            if Bundler.rubygems.spec_missing_extensions?(s, false)
              Bundler.ui.debug "Source #{self} is ignoring #{s} because it is missing extensions"
              next
            end
            idx << s
          end

          idx
        end
      end