# File lib/rubygems/source_index.rb, line 89
      def load_specification(file_name)
        begin
          spec_code = File.read(file_name).untaint
          gemspec = eval(spec_code)
          if gemspec.is_a?(Gem::Specification)
            gemspec.loaded_from = file_name
            return gemspec
          end
          alert_warning "File '#{file_name}' does not evaluate to a gem specification"
        rescue SyntaxError => e
          alert_warning e
          alert_warning spec_code
        rescue Exception => e
          alert_warning(e.inspect.to_s + "\n" + spec_code)
          alert_warning "Invalid .gemspec format in '#{file_name}'"
        end
        return nil
      end