anchor.diff:  let
   
     inherit (pkgs.lib) mkOption;
  -  inherit (config) urlPrefix distDir;
   
  -  dataDir = "/data/pt-wiki/data";
  -  pubDir = "/data/pt-wiki/pub";
  +  dataDir = config.dataDir; # "/data/pt-wiki/data";
  +  pubDir = config.pubDir; # "/data/pt-wiki/pub";
   
     scriptUrlPath = "/bin";
     pubUrlPath    = "/pub";
  
positive.code:     Disallow: /pt/bin/
    '';
  
  }
negative.code:   dispScriptUrlPath = "";
    dispViewPath      = "";
  
    startWeb = config.startWeb;
    defaultUrlHost = "";
  
    # Build the TWiki CGI and configuration files.
    twikiRoot = (import /etc/nixos/services/twiki/twiki-instance.nix).twiki {
      name = "wiki-instance";
      pubdir = pubDir;
      datadir = dataDir;
      inherit scriptUrlPath pubUrlPath absHostPath
        dispPubUrlPath dispScriptUrlPath dispViewPath defaultUrlHost;
      twikiName = config.twikiName;
      registrationDomain = config.registrationDomain;
    };
  
    plugins = import /etc/nixos/services/twiki/server-pkgs/twiki-plugins.nix;
  