anchor.diff:          };
           inherit fromImage fromImageName fromImageTag;
   
  -        buildInputs = [ utillinux e2fsprogs jshon rsync jq ];
  +        nativeBuildInputs = [ utillinux e2fsprogs jshon rsync jq ];
         } ''
         rm -rf $out
   
  
positive.code:   # We need to sum layer.tar, not a directory, hence tarsum instead of nix-hash.
    # And we cannot untar it, because then we cannot preserve permissions ecc.
    tarsum = runCommand "tarsum" {
      buildInputs = [ go ];
    } ''
      mkdir tarsum
      cd tarsum
  
negative.code:   }:
      runCommand "docker-layer-${name}" {
        inherit baseJson contents extraCommands;
        nativeBuildInputs = [ jshon rsync tarsum ];
      }
      ''
        mkdir layer
  