It has to do with installing packages that use PAM to e.g. validate user passwords (e.g. display managers, screen lockers). So there is a system PAM with its co

It has to do with installing packages that use PAM to e.g. validate user passwords (e.g. display managers, screen lockers). So there is a system PAM with its configuration, but making a program packaged with nix respect that system PAM config is not as easy as just linking with libpam from nixpkgs.