def find_missing(spec_names)
      unless defined? @originals then
        @originals = {}
        each do |full_name, spec|
          @originals[spec.original_name] = spec
        end
      end

      spec_names.find_all { |full_name|
        @originals[full_name].nil?
      }
    end
def find_missing(spec_names)
      unless defined? @originals then
        @originals = {}
        each do |full_name, spec|
          @originals[spec.original_name] = spec
        end
      end

      spec_names.find_all { |full_name|
        @originals[full_name].nil?
      }
    end
Make a list of full names for all the missing gemspecs.