On Sun, Oct 28, 2012 at 12:29 PM, Giorgio Lando <giorgio.lando@gmail.com> wrote:
"Note: Adding your user to groups (optical, audio, scanner, ...) is not necessary with systemd. It might even break the wanted functionality if you do so."
While I ignore the technical reasons, my scanner does not work if I am not in the scanner group.
That is a bug (or potentially a misconfiguration, though I cannot imagine exactly how). The way it should work is: The udev rules shipped with sane (53-sane.rules) will make the scanner group the owner of your scanner device and add an environment variable for the device: "ENV{libsane_matche}=yes" to the udev db. Based on this variable, the rules shipped with logind (70-uaccess.rules) will add the "uaccess" tag to the udev db for the scanner device. That tag is what tells logind which devices to assign ACL's to (as described by Zeke earlier in this thread). If you are having a problem with this, please open a bug report, making sure that you are running systemd, that your user session is registered and considered active by logind (use loginctl to check) and that sane is installed. Attach the output of "udevadm info /dev/<your scanner>" to the bug report. Cheers, Tom