# File lib/nanoc/cli/commands/compile.rb, line 217
    def start_filter_progress(rep, filter_name)
      # Only show progress on terminals
      return if !$stdout.tty?

      @progress_thread = Thread.new do
        delay = 1.0
        step  = 0

        text = "Running #{filter_name} filter… ".make_compatible_with_env

        while !Thread.current[:stopped]
          sleep 0.1

          # Wait for a while before showing text
          delay -= 0.1
          next if delay > 0.05

          # Print progress
          $stdout.print text + %w( | / - \\ )[step] + "\r"
          step = (step + 1) % 4
        end

        # Clear text
        if delay < 0.05
          $stdout.print ' ' * (text.length + 1 + 1) + "\r"
        end
      end
    end