# File lib/compass/commands/project_base.rb, line 65
      def detect_configuration_file
        if options[:configuration_file]
          if explicit_config_file_must_be_readable? && !File.readable?(options[:configuration_file])
            raise Compass::Error, "Configuration file, #{file}, not found or not readable."
          end
          return options[:configuration_file]
        end
        KNOWN_CONFIG_LOCATIONS.map{|f| projectize(f)}.detect{|f| File.exists?(f)}
      end