Klipppy logs state that serial device can't be found about prind HOT 4 CLOSED

OK so go ahead and disregard the above, I hadn't realized I copied over the [mcu] section in the printer.cfg file and set a bad path to the serial device.

HOWEVER now that I figured that out and changed it back to ttymxc3 it also didn't work, the logs said there's a permission error. So I tried swapping it out to test with ttyUSB0 and I got the same result. I attached into the container and checked /dev/ and was able to confirm that the device is in there. Here is the bottom of the log as proof:

mcu 'mcu': Starting serial connect
mcu 'mcu': Unable to open serial port: [Errno 13] could not open port /dev/ttyUSB0: [Errno 13] Permission denied: '/dev/ttyUSB0'
webhooks client 139665361786272: New connection
webhooks client 139665361786272: Client info {'program': 'Moonraker', 'version': '?'}
mcu 'mcu': Unable to open serial port: [Errno 13] could not open port /dev/ttyUSB0: [Errno 13] Permission denied: '/dev/ttyUSB0'

from prind.

Had the same problem on arch linux. Try to add permission to the serial port on a host machine: chmod 666 /dev/ttyUSB0 (or ttyACM0 in my case).
Not sure if this is the good solution but it works for me

upd: Unfortunately it will work only for current session (until reboot or printer re-plug/reset)

Alternative solution is to create a file printer.rules in /etc/udev/rules.d/ with some rules in it:
KERNEL=="video[0-9]*", SUBSYSTEM=="video4linux", SUBSYSTEMS=="usb", MODE="0666"
KERNEL=="ttyUSB[0-9]*", MODE="0666"
KERNEL=="ttyACM[0-9]*", MODE="0666"

and then execute:
# udevadm control --reload

from prind.

My first reaction would be to set udev rules as @ximikator suggested.
Check the file permissions on your printers serial port.

ls -al /dev
docker compose exec klipper ls -al /dev

Also, run the get-info Script and attach the generated archive to this issue.

./scripts/get-info.sh

-Markus

from prind.

udev rules worked fine

from prind.