NixOS/nixpkgs — pull request #5329 by iElectric (2014-12-14 12:51:33+00:00)
Title: if users.mutableUsers is false, require root password to be set

Running `nixos-install` with `users.mutableUsers = false;` currently doesn't work. Following PR requires root password to be set once immutable users are used.

Also fixes #3788