# File lib/compass/compiler.rb, line 84
    def run
      failure_count = 0
      if new_config?
        # Wipe out the cache and force compilation if the configuration has changed.
        remove options[:cache_location] if options[:cache_location]
        options[:force] = true
      end

      # Make sure the target directories exist
      target_directories.each {|dir| directory dir}

      # Compile each sass file.
      result = timed do
        sass_files.zip(css_files).each do |sass_filename, css_filename|
          begin
            compile_if_required sass_filename, css_filename
          rescue Sass::SyntaxError => e
            failure_count += 1
            handle_exception(sass_filename, css_filename, e)
          end
        end
      end
      if options[:time]
        puts "Compilation took #{(result.__duration * 1000).round / 1000.0}s"
      end
      return failure_count
    end