My system configuration doesn’t set security.loginDefs.settings.UMASK. As a result, its default value of "077" should apply, and indeed /etc/login.defscontains UMASK 077 as its last line. However, when logging in as an ordinary user, I find umask been set to 022. Why is this? How can I change this, preferably via configuration.nix?
I’m using NixOS 25.05.