Just try sudo ./flash.sh jetson-xavier-nx-devkit-emmc mmcblk0p1
That -K DTB does not work on jetson xavier series. Also, refer to the Quick start guide document for using this tool.
The log is just that info dumped on your host side terminal. You only dumped the log after second 8.
[ 8.3066 ] /usr/bin/env: Traceback (most recent call last):
File “./tegraflash.py”, line 1296, in
tegraflash_run_commands()
File “./tegraflash.py”, line 1155, in tegraflash_run_commands
interpreter.onecmd(command)