anchor.diff:  
         postMount = ''
           echo "Packing raw image..."
  -        tar -C mnt --mtime="@$SOURCE_DATE_EPOCH" -cf $out .
  +        tar -C mnt --hard-dereference --mtime="@$SOURCE_DATE_EPOCH" -cf $out .
         '';
       };
   
  
positive.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..."
  
negative.code:       # Tar up the layer and throw it into 'layer.tar'.
        echo "Packing layer..."
        mkdir $out
        tar -C layer --hard-dereference --mtime="@$SOURCE_DATE_EPOCH" --owner=${toString uid} --group=${toString gid} -cf $out/layer.tar .
  
        # Compute a checksum of the tarball.
        echo "Computing layer checksum..."
  