Thanks for running these tests!
That is a surprising result. The changes in the identified commit appear mostly harmless. I’ll take a closer look at the code, but I suspect the error exists in prior revisions, but the probability of it showing is so low that it is hard to test. Some of your reports have frequency: 1 time and I fear it may have just been (bad) luck that it got caught that time.
For completeness could you run a test of the code at Ensure minimum time between step pin and dir pin change by KevinOConnor · Pull Request #6926 · Klipper3d/klipper · GitHub ? There’s some info on testing a PR at Testing Klipper Pull Requests . (The code on that PR is a later evolution of the code I also mentioned at Issues with stepper drift on latest Klipper - #26 by koconnor ). That PR is on top of the mainline branch, so an error should show up rapidly if it is still faulty. (Be sure to “make menuconfig”, “make flash”, “sudo service klipper restart”, etc. )
Thanks again,
-Kevin