printf '100644 file1.txt\x00\x6a\xd3\x6e\x52\xf0\x00\x29\x37\xed\x2d\xe6\xa1\xc1\x5d\x8a\x0a\xe5\xdf\x05\x6a' | tee /tmp/tree1-data | wc -c
# 37
printf 'tree 37\x00' > /tmp/tree1
cat /tmp/tree1-data >> /tmp/tree1
sha1sum /tmp/tree1
# d20f1946b531ca91c8e08744c48811593092f23f  /tmp/tree1
mkdir .git/objects/d2
deflate < /tmp/tree1 > .git/objects/d2/0f1946b531ca91c8e08744c48811593092f23f
rm /tmp/tree1 /tmp/tree1-data