Exception in flush handler

General Discussion
1

Basic Information:

Printer Model: Troodon 2 (originally reprap, now klipper)
MCU / Printerboard: Octopus X7
Host / SBC Rasp pi 5
klippy.log

klippy(exception in flush handler) 10 8 25.log (312.6 KB)

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Describe your issue:

Hi all, I could use some help troubleshooting an issue I’ve been having since adding a stealthmax 2 to this printer.

The klippy I’ve attached is about as short as it can be as I’ve been trying to trace this issue. It has happened ~5 times, with at least three of those occurring from trying to unload filament after a print.

I see that more than likely I’ll be pointed to the klipper version running on this printer being dirty. I’ve reached out to the person responsible for the nevermore software and they’ve indicated this isn’t or shouldn’t be an issue with that software. I have not reached out to anyone responsible for the led effects software.

Looking at the klippy log (I’m not experienced at understanding what I see there), it appears that the primary error is ‘extruder’ step generation. But I don’t know if or how to tell if that error stems from something that nevermore or led effects is leaving to be flushed that klipper isn’t handling.

I would appreciate any insight as to how to solve this. If the issue is with the led effect, I could obviously live without. But I added the filter to the printer because it’s important to me, I use two printers at work in a small room printing ESD fixtures, and want to take all precautions to help ensure I’m not breathing dirty air.

I suppose I could always see about setting up the stealthmax fan as generic and letting klipper control it, but then I lose a few valuable tools that come with nevermore(temp and humidity sensors), and I would almost prefer just dealing with the error(rebooting) as it arises to maintain those.

Thanks to any and all taking the time to read, any insight is greatly appreciated.

2

Is there a coincidence to this thread? Exception in flush_handler - #3 by 3dcoded

3

Definitely some similarities. In the error for sure, it looks very similar. I had looked at that prior to posting my topic, and I suppose I assumed that their issue might or would be solved through the happy hare update, which I am not using. Nevermore and led effects are up to date on my machine, and ultimately I’m looking for more insight as to tracing the issue to its’ root.

The similarities between the other post and mine might suggest it could be related to the led effects.

Would you expect that if I comment out the led effects section of my config, that would be enough to test if that is causing the issue? Or is it necessary to rebuild klipper to test because the presence of led effects may still cause issues?

Oh, and not to divert or make this any more complicated, but while trying to sort this out I noticed that the printerboard is running older klipper than the host. Could that be causing this error?

klipper verisons og 10 8 25
klipper verisons og 10 8 25641×256 12.1 KB

Thanks again for your time.

4

The upstream Klipper repository had an error (commit b60804bb - applied on September 15th) that was recently fixed (commit c49dbb5a - applied on October 4th). The error could result in sporadic “step compress errors”. It is recommended to update to the latest code to avoid the issue.

-Kevin

5

I’m marking this as solved as Kevin suggested the fix and I haven’t had issues since updating. Though to be fair I haven’t been able to print/test as much as I’d like, but I’m assuming this is solved.