Nixos-rebuild build-image fails with "default.nix': No such file or directory" when using flake flag

Trying to create my own lxc containers, and I am kind of running blind because the manual section for nixos-rebuild build-image doesn’t include any examples of usage. Correct me if I’m wrong, but if I’m running the following command: nixos-rebuild build-image --flake . --image-variant lxc a default.nix shouldn’t be necessary no? In case its pertinent, heres the flake: { description = "Forgejo server"; inputs = { nixpkgs.url = "github:nixos/nixpkgs/nixos-26.05"; }; outputs = { self...