anchor.diff:          echo "Adding contents..."
           for item in ${toString contents}; do
             echo "Adding $item..."
  -          rsync -ak $item/ layer/
  +          rsync -ak --chown=0:0 $item/ layer/
           done
         '';
   
  
positive.code:       # Tar up the layer and throw it into 'layer.tar'.
        echo "Packing layer..."
        mkdir $out
        tar -C layer --mtime=0 -cf $out/layer.tar .
  
        # Compute a checksum of the tarball.
        echo "Computing layer checksum..."
  
negative.code: 
          echo "Packing layer..."
          mkdir $out
          tar -C layer --mtime="@$SOURCE_DATE_EPOCH" -cf $out/layer.tar .
  
          # Compute the tar checksum and add it to the output json.
          echo "Computing checksum..."
  