$ git diff-tree --root -r --abbrev initial
444ac553ac7612cc88969031b02b3767fb8a353a
:000000 100644 0000000... 35d242b... A	dir/sub
:000000 100644 0000000... 01e79c3... A	file0
:000000 100644 0000000... 01e79c3... A	file2
$