Package: light Version: 1.2.2-2 Executing light commands that would modify the backlight brightness, for example setting the brightness to 10%: ~$ light -S 10 do not work when run as a non-root user, even if that user is a member of the "video" group. The upstream author suggests "video" membership is the intended mechanism to grant non-root users the necessary privilege to modify backlight settings. su'ing to root and then executing the same commands successfully modifies the backlight brightness.
Looking at the upstream git repo there is a udev rule included as part of the source distribution: https://github.com/haikarainen/light/blob/master/90-backlight.rules Manually copying these rules into /etc/udev/rules.d/ allowed my unpriviledged user to modify the backlight brightness on the condition that I was a member of the "video" group. This seems more attractive than manually making /usr/bin/light SUID. Currently running Bullseye 11.1, kernel 5.14.9-2~bpo11+1, glibc 2.31-13+deb11u2. For hardware, I'm using a Framework laptop which appears to use /sys/class/backlight/intel_backlight/ for getting and setting backlight options.
