ignore first commit error

hooks/update.format.full

@@ -3,6 +3,7 @@ set -u
 set -e
 
 ref_name=$1
+old_rev=$2
 new_rev=$3
 
 # Here you can use whatever formatter you like
@@ -51,6 +52,10 @@ refs/heads/*)
 	#
 	# ex: /tmp/git-work-tree.abc123xyz
 	my_work_tree=$(mktemp -d -t git-work-tree.XXXXXXXX) 2>/dev/null
+	if [ "$(expr "${old_rev}" : '0*$')" -ne 0 ]; then
+		# Ignore "fatal: You are on a branch yet to be born"
+		set +e
+	fi
 	git --work-tree="${my_work_tree}" --git-dir="." checkout -f >/dev/null
 	my_changes=$(git --work-tree="${my_work_tree}" --git-dir="." diff --name-status HEAD $new_rev)
 	if [ -n "$(echo "$my_changes" | grep -e "^A")" ]; then