For the 2FA key, pam_u2f depends on the existence of /etc/u2f_mappings at run time. Without it, it'll fall back to password auth.
pamu2fcfg > /etc/u2f_mappings
Build config
sudo nixos-rebuild --flake .#HOSTNAME build
Hostnames:
- Desktop (
machine) - Laptop (
elbozo) - Server (
slave)