anchor.diff:  provides "nginx"
   provides "nginx/version"
   provides "nginx/configure_arguments"
  -provides "nginx/modules"
   provides "nginx/prefix"
   provides "nginx/conf_path"
   
   def parse_flags(flags)
     prefix = nil
     conf_path = nil
  -  ngx_modules = Array.new
   
     flags.each do |flag|
       case flag
  
positive.code:       # add the '--' prefix back to the configure argument.
        nginx[:configure_arguments] = $1.split(/\s--/).drop(1).map { |ca| "--#{ca}" }
  
        prefix, conf_path, ngx_modules = parse_flags(nginx[:configure_arguments])
  
        nginx[:prefix] = prefix
        nginx[:conf_path] = conf_path
        nginx[:modules] = ngx_modules
      when /^nginx version: nginx\/(.+)/
        nginx[:version] = $1
      end
  
negative.code:       prefix = $1
      when /^--conf-path=(.+)$/
        conf_path = $1
      end
    end
  
    [ prefix, conf_path ]
  end
  
  nginx Mash.new unless nginx
  nginx[:version]             = nil unless nginx[:version]
  nginx[:configure_arguments] = Array.new unless nginx[:configure_arguments]
  nginx[:prefix]              = nil unless nginx[:prefix]
  nginx[:conf_path]           = nil unless nginx[:conf_path]
  
  