anchor.diff:        preStart =
           ''
           ${cfg.preStart}
  -        ${cfg.package}/bin/nginx -c ${configFile}/nginx.conf -p ${cfg.stateDir} -t
  +        ${cfg.package}/bin/nginx -c ${configFile} -p ${cfg.stateDir} -t
           '';
         serviceConfig = {
  -        ExecStart = "${cfg.package}/bin/nginx -c ${configFile}/nginx.conf -p ${cfg.stateDir}";
  +        ExecStart = "${cfg.package}/bin/nginx -c ${configFile} -p ${cfg.stateDir}";
           ExecReload = "${pkgs.coreutils}/bin/kill -HUP $MAINPID";
           Restart = "always";
           RestartSec = "10s";
  
positive.code:     }
    ''));
  
    awkFormat = pkgs.writeText "awkFormat-nginx.awk" ''
      awk -f
      {sub(/^[ \t]+/,"");idx=0}
      /\{/{ctx++;idx=1}
  
negative.code:     {id="";for(i=idx;i<ctx;i++)id=sprintf("%s%s", id, "\t");printf "%s%s\n", id, $0}
    '';
  
    configFile = pkgs.runCommand "nginx.conf" {} (''
      awk -f ${awkFormat} ${pre-configFile} | sed '/^\s*$/d' > $out
    '');
  
    pre-configFile = pkgs.writeText "pre-nginx.conf" ''
      user ${cfg.user} ${cfg.group};
  