anchor.diff:  
   let
   
  +  versionSuffix = "pre${toString nixosSrc.rev}-${toString nixpkgs.rev}";
  +
   
     makeIso =
       { module, type, description ? type, maintainers ? ["eelco"] }:
       { officialRelease ? false
  -    , system ? "i686-linux"
  +    , system ? builtins.currentSystem
       }:
   
       with import <nixpkgs> {inherit system;};
   
       let
   
  -      version = builtins.readFile ./VERSION + (if officialRelease then "" else "pre${toString nixosSrc.rev}");
  +      version = builtins.readFile ./VERSION + (lib.optionalString (!officialRelease) versionSuffix);
   
         versionModule =
           { system.nixosVersion = version;
  
positive.code:           '';
  
          distPhase = ''
            releaseName=nixos-$VERSION$VERSION_SUFFIX-${toString nixpkgs.rev}
            ensureDir "$out/tarballs"
            mkdir ../$releaseName
            cp -prd . ../$releaseName/nixos
  
negative.code:   makeSystemTarball =
      { module, maintainers ? ["viric"]}:
      { officialRelease ? false
      , system ? builtins.currentSystem
      }:
  
      with import <nixpkgs> {inherit system;};
      let
        version = builtins.readFile ./VERSION + (lib.optionalString (!officialRelease) versionSuffix);
  
        versionModule = { system.nixosVersion = version; };
  
  