# File sprout/lib/sprout/tasks/tool_task.rb, line 580
    def preprocess_content(readable, writable, processor, file)
      process = ProcessRunner.new(processor)
      process.puts(readable.read)
      process.close_write
      result = process.read
      error = process.read_err
      if(error.size > 0)
        belongs_to.display_preprocess_message
        FileUtils.rm_rf(belongs_to.preprocessed_path)
        raise ExecutionError.new("[ERROR] Preprocessor failed on file #{file} #{error}")
      end
      writable.write(result)
    end