anchor.diff:        [ (packageByName package) ]
       else if maintainer != null then
         packagesWithUpdateScriptAndMaintainer maintainer
  +    else if path != null then
  +      packagesWithUpdateScript path
       else
         builtins.throw "No arguments provided.\n\n${helpText}";
   
  
positive.code:                    (name: pkg: pkg)
                     pkgs;
  
    packageByName = name:
      let
          package = pkgs.lib.attrByPath (pkgs.lib.splitString "." name) null pkgs;
  
negative.code: 
          % nix-shell maintainers/scripts/update.nix --argstr package garbas
  
      to run update script for specific package, or
  
          % nix-shell maintainers/scripts/update.nix --argstr path gnome3
  
      to run update script for all package under an attribute path.
    '';
  
    runUpdateScript = package: ''
  