anchor.diff:                 then mkPureLayer { inherit baseJson contents extraCommands; }
                  else mkRootLayer { inherit baseJson fromImage fromImageName fromImageTag contents runAsRoot diskSize extraCommands; });
         result = runCommand "${baseName}.tar.gz" {
  -        buildInputs = [ jshon ];
  +        buildInputs = [ jshon pigz ];
   
           imageName = name;
           imageTag = tag;
  
positive.code:         chmod -R a-w image
  
          echo Cooking the image
          tar -C image -czf $out .
        '';
  
      in
  
negative.code: { stdenv, lib, callPackage, runCommand, writeReferencesToFile, writeText, vmTools, writeScript
  , docker, shadow, utillinux, coreutils, jshon, e2fsprogs, goPackages, pigz }:
  
  # WARNING: this API is unstable and may be subject to backwards-incompatible changes in the future.
    
  