led_defaults can not be found

root@MOXjp:~# rainbow brightness -q
000
root@MOXjp:~# rainbow brightness 1
/usr/libexec/rainbow/uci.sh: line 67: type: led_defaults: not found
/usr/libexec/rainbow/uci.sh: line 67: type: led_defaults: not found
Command failed: Not found
Command failed: Not found
root@MOXjp:~# rainbow brightness -p 1
/usr/libexec/rainbow/uci.sh: line 67: type: led_defaults: not found
/usr/libexec/rainbow/uci.sh: line 67: type: led_defaults: not found
Command failed: Not found
Command failed: Not found

Reported here: https://forum.turris.cz/t/turris-os-6-0-is-now-in-hbt-testing-branch/17776/99?u=pepe