anchor.diff:  
         echo "copying store paths to image..."
         cptofs -t ext4 -i $out $storePaths /nix/store/
  +
  +      (
  +      echo "copying files to image..."
  +      cd ./files
  +      cptofs -t ext4 -i $out ./* /
  +      )
   
         # I have ended up with corrupted images sometimes, I suspect that happens when the build machine's disk gets full during the build.
         if ! fsck.ext4 -n -f $out; then
  
positive.code: # Builds an ext4 image containing a populated /nix/store with the closure
  # of store paths passed in the storePaths parameter. The generated image
  # is sized to only fit its contents, with the expectation that a script
  # resizes the filesystem at boot time.
  { pkgs
  , storePaths
  , volumeLabel
  , uuid ? "44444444-4444-4444-8888-888888888888"
  , e2fsprogs
  
negative.code: 
    buildCommand =
      ''
        (
        mkdir -p ./files
        ${populateImageCommands}
        )
        # Add the closures of the top-level store objects.
        storePaths=$(cat ${sdClosureInfo}/store-paths)
  
        # Make a crude approximation of the size of the target image.
        # If the script starts failing, increase the fudge factors here.
        numInodes=$(find $storePaths ./files | wc -l)
        numDataBlocks=$(du -s -c -B 4096 --apparent-size $storePaths ./files | tail -1 | awk '{ print int($1 * 1.03) }')
        bytes=$((2 * 4096 * $numInodes + 4096 * $numDataBlocks))
        echo "Creating an EXT4 image of $bytes bytes (numInodes=$numInodes, numDataBlocks=$numDataBlocks)"
  
  