colord-sane: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied

Question

I get the following errors all in a row in my journalctl after booting:

colord-sane[4901]: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied
colord-sane[4901]: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied
colord-sane[4901]: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied
colord-sane[4901]: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied
colord-sane[4901]: io/hpmud/musb.c 2101: Invalid usb_open: Permission denied

I don't know if it's related to this post, but the permission denied issue looks very similar. I tried going through those steps looking for parallels between saned and colord-sane but wasn't sure what user to add to which file, or what group it needed to be added to.

Answer 1

I opened lib/systemd/system/colord.service and noticed it had User=colord.

So I tried adding the colord user to the lp group:

sudo usermod -a -G lp colord

And, after a reboot, the error is gone! I hope this helps if you have a similar error.