Thanks Samuel! 
It appears to work now since pulling your latest devel (b178357 - fix DFU).
Although it does exit with another backtrace:
towen:~/GitHub/ODrive$ tools/odrivetool dfu Firmware/build/ODriveFirmware.hex
ODrive control utility v0.5.1.dev
Waiting for ODrive...
22:16:37.86599134 [USB] Could not open USB device: -3
22:16:37.87095455 [USB] Could not claim interface on USB device: -6
22:16:37.87165179 [USB] Could not claim interface on USB device: -6
22:16:37.87509617 [USB] Could not open USB device: -3
... [some lines omitted]
22:16:37.89644333 [USB] Could not open USB device: -3
Found ODrive 205639994D4D (v3.6-56V) with firmware v0.5.1-dev
Warning: you are about to flash firmware [unknown version] which is older than the firmware on the device (v0.5.1-dev).
Do you want to flash this firmware anyway? [y/N] y
Saving configuration to /tmp/odrive-config-205639994D4D.json...
The file /tmp/odrive-config-205639994D4D.json already exists. Do you want to override it? [Y/n]
Configuration saved.
Putting device 205639994D4D into DFU mode...
Erasing... done
Flashing... done
Verifying... done
Waiting for the device to reappear...
22:17:01.605846893 [USB] Could not open USB device: -3
... [ a few more lines omitted]
22:17:01.608797440 [USB] Could not open USB device: -3
22:17:03.880847691 [USB] Could not claim interface on USB device: -6
22:17:03.881003484 [USB] Could not claim interface on USB device: -6
Restoring configuration from /tmp/odrive-config-205639994D4D.json...
Could not restore axis0.controller.config.anticogging.calib_anticogging: 'anonymous_interface_140527438462672' object has no attribute 'exchange'
Could not restore axis0.controller.config.anticogging.cogging_ratio: 'anonymous_interface_140527438457568' object has no attribute 'exchange'
Could not restore axis0.controller.config.anticogging.index: 'anonymous_interface_140527438464960' object has no attribute 'exchange'
Could not restore axis1.controller.config.anticogging.calib_anticogging: 'anonymous_interface_140527438462672' object has no attribute 'exchange'
Could not restore axis1.controller.config.anticogging.cogging_ratio: 'anonymous_interface_140527438457568' object has no attribute 'exchange'
Could not restore axis1.controller.config.anticogging.index: 'anonymous_interface_140527438464960' object has no attribute 'exchange'
Some of the configuration could not be restored.
Traceback (most recent call last):
File "/home/towen/GitHub/ODrive/tools/odrivetool", line 148, in <module>
odrive.dfu.launch_dfu(args, logger, app_shutdown_token)
File "/home/towen/GitHub/ODrive/tools/odrive/dfu.py", line 465, in launch_dfu
update_device(device, firmware, logger, cancellation_token)
File "/home/towen/GitHub/ODrive/tools/odrive/dfu.py", line 429, in update_device
odrive.configuration.restore_config(device, None, logger)
File "/home/towen/GitHub/ODrive/tools/odrive/configuration.py", line 100, in restore_config
device.save_configuration()
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 573, in __call__
return run_coroutine_threadsafe(self._libfibre.loop, lambda: self.__call__(*args))
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 288, in run_coroutine_threadsafe
return future.result()
File "/usr/lib/python3.9/concurrent/futures/_base.py", line 440, in result
return self.__get_result()
File "/usr/lib/python3.9/concurrent/futures/_base.py", line 389, in __get_result
raise self._exception
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 283, in func_async
result = await result
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 540, in async_call
tx_buf, rx_chunk, is_closed = await agen.asend((tx_buf, self._rx_size - len(rx_buf), True))
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 462, in asend
return await self.__anext__()
File "/home/towen/GitHub/ODrive/tools/odrive/pyfibre/fibre/libfibre.py", line 491, in __anext__
raise _get_exception(status)
fibre.libfibre.ObjectLostError: the object disappeared
towen:~/GitHub/ODrive$
(and apparently the version I had when I did the encoder tests was 0.5.1-dev, although I was sure I had flashed it with a newer one - I will try the encoder again now)
