
Previously systemd-networkd.service ran as systemd-network:nogroup. The wireguard private key file is now owned by root:systemd-network with mode 0640. It is therefore required that the systemd-network user is in the group with the same name, so that it is able to read the key file.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.