MMU Shutdown after updating to 3.1

[florek41]

Hi, I have a problem after most recent update - 3.1
I'm gettin all sorts of errors
For example - during homing MMU I've got

Internal error on command:"MMU_HOME"

Internal Error on WebRequest: gcode/script
Traceback (most recent call last):
  File "/home/bartek/klipper/klippy/webhooks.py", line 256, in _process_request
    func(web_request)
  File "/home/bartek/klipper/klippy/webhooks.py", line 436, in _handle_script
    self.gcode.run_script(web_request.get_str('script'))
  File "/home/bartek/klipper/klippy/gcode.py", line 229, in run_script
    self._process_commands(script.split('\n'), need_ack=False)
  File "/home/bartek/klipper/klippy/gcode.py", line 211, in _process_commands
    handler(gcmd)
  File "/home/bartek/klipper/klippy/gcode.py", line 137, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 6022, in cmd_MMU_HOME
    self.home(tool, force_unload=force_unload)
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 5684, in home
    self.selector.home(force_unload=force_unload)
  File "/home/bartek/klipper/klippy/extras/mmu/mmu_selector.py", line 331, in home
    self.mmu.unload_sequence()
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 4841, in unload_sequence
    self._unload_gate(homing_max=bowden_move) # Full slow unload
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 4107, in _unload_gate
    success = self._reverse_home_to_encoder(homing_max)
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 4135, in _reverse_home_to_encoder
    for i in range(max_steps):
TypeError: range() integer end argument expected, got float.
MCU 'mmu' shutdown: Command request

After restart I've got
Internal error on command:"__MMU_SENSOR_INSERT"
Internal error on command:"MMU_PRELOAD"

Internal error on command:"MMU_PRELOAD"
Traceback (most recent call last):
  File "/home/bartek/klipper/klippy/gcode.py", line 211, in _process_commands
    handler(gcmd)
  File "/home/bartek/klipper/klippy/gcode.py", line 137, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 8082, in cmd_MMU_PRELOAD
    self._preload_gate()
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 3976, in _preload_gate
    self._unload_gate()
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 4107, in _unload_gate
    success = self._reverse_home_to_encoder(homing_max)
  File "/home/bartek/klipper/klippy/extras/mmu/mmu.py", line 4135, in _reverse_home_to_encoder
    for i in range(max_steps):
TypeError: range() integer end argument expected, got float.
Transition to shutdown state: Internal error on command:"MMU_PRELOAD"

and looks like it traces to the same place.
Any ideas?

klippy (19).log

[bombela]

Same error here.

Internal error on command:"MMU_CALIBRATE_BOWDEN"
Traceback (most recent call last):
  File "/home/pi/klipper/klippy/gcode.py", line 212, in _process_commands
    handler(gcmd)
  File "/home/pi/klipper/klippy/gcode.py", line 140, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 2582, in cmd_MMU_CALIBRATE_BOWDEN
    length, clog = self._calibrate_bowden_length_auto(approx_bowden_length, extruder_homing_max, repeats)
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 2297, in _calibrate_bowden_length_auto
    self._unload_gate()
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 4107, in _unload_gate
    success = self._reverse_home_to_encoder(homing_max)
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 4135, in _reverse_home_to_encoder
    for i in range(max_steps):
TypeError: range() integer end argument expected, got float.
Transition to shutdown state: Internal error on command:"MMU_CALIBRATE_BOWDEN"

Happy Hare 395db13

[bombela]

And after this, nothing works anymore.

Internal error on command:"MMU_HOME"
Once the underlying issue is corrected, use the
"FIRMWARE_RESTART" command to reset the firmware, reload the
config, and restart the host software.
Printer is shutdown

Internal error on command:"MMU_HOME"
Internal Error on WebRequest: gcode/script
Traceback (most recent call last):
  File "/home/pi/klipper/klippy/webhooks.py", line 256, in _process_request
    func(web_request)
  File "/home/pi/klipper/klippy/webhooks.py", line 436, in _handle_script
    self.gcode.run_script(web_request.get_str('script'))
  File "/home/pi/klipper/klippy/gcode.py", line 230, in run_script
    self._process_commands(script.split('\n'), need_ack=False)
  File "/home/pi/klipper/klippy/gcode.py", line 212, in _process_commands
    handler(gcmd)
  File "/home/pi/klipper/klippy/gcode.py", line 140, in <lambda>
    func = lambda params: origfunc(self._get_extended_params(params))
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 6022, in cmd_MMU_HOME
    self.home(tool, force_unload=force_unload)
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 5684, in home
    self.selector.home(force_unload=force_unload)
  File "/home/pi/klipper/klippy/extras/mmu/mmu_selector.py", line 331, in home
    self.mmu.unload_sequence()
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 4841, in unload_sequence
    self._unload_gate(homing_max=bowden_move) # Full slow unload
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 4107, in _unload_gate
    success = self._reverse_home_to_encoder(homing_max)
  File "/home/pi/klipper/klippy/extras/mmu/mmu.py", line 4135, in _reverse_home_to_encoder
    for i in range(max_steps):
TypeError: range() integer end argument expected, got float.

[bombela]

Same error on the v3.1.0 tag. 4863e64 (tag: v3.1.0)

[moggieuk]

This isn't a change in HH but something in the environment... Hmm. Did you upgrade OS / python?

[bombela]

I am not sure exactly how I fixed it. Here is an account of what happened.

After getting TypeError: range() integer end argument expected, got float. various version of Happy Hare, I threw a fit, powered off the printer and walked away.

A day later, moonraker refuses to start, complaining about some syntax error. Which as far as I can tell was coming from klipper itself.

For some reason, klipper was running in a python2 env, while moonraker was running under its own python3 env. How comes it worked the day prior far enough to start moonraker/mainsail, but not anymore? No idea. I even double checked the systemd units, and they did not look different. Clearly something changed that the reboot reloaded.

I fully removed python2 from the whole machine as an extra precaution. And re-created a python3 env for klipper. Then I update Happy Hare to the latest main branch (some changes landed over night).

And everything is now working fine. Interestingly, Happy Hare also stopped complaining about a lack of completed calibration.

I still cannot explain how klipper managed to work under python2 one day and not the next. And why moonraker worked and then not anymore. But I must have had something loaded that a reboot cleared.

[moggieuk]

100% sure this wan't a change in HH. Anyway, I've added a precaution to the code (and pushed an update). This will force an integer. FWIW the code is using:
math.ceil() to generate the number of movement. This is an integer! However (apparently) it is possible for some version's of Python 2 to return a float!!!! I suspect some other update caused python2 to misbehave. This would cause havoc with klipper too...

Final note: Python 2 is a dead language. I support it because Klipper does, but you really should upgrade to python 3.

[bombela]

Thank you for the details @moggieuk.

Back when I installed klipper with kiauth, it created a python2 venv. I used kiauth to handle the updates for me. Which apparently doesn't warn about python2 nor re-create a python3 env during updates.

I am still on the ERCFv1. And Happy Hare is handling it very well so far. Thank you for the fantastic work.

The original encoder is still working perfectly ;)

Load direction:   mean=605.00 stdev=0.00 min=605 max=605 range=0
Unload direction: mean=605.00 stdev=0.00 min=605 max=605 range=0