Install libnss-rainbow2 by entering the following commands in the terminal:
sudo apt update sudo apt install libnss-rainbow2
nss library for rainbow
Rainbow is a isolation shell which implements portions of the Bitfrost security architecture, as used on the OLPC XO-1 and elsewhere. . This package contains an "Name Service Switch" plugin for glibc which permits Rainbow to easily create and remove users and groups without modifying /etc/passwd and /etc/group.