Diff NixOS configurations.
nixos-diff ./config1.nix ./config1.nix
nixos-diff ./config1.nix
nixos-diff --expr 'import <nixpkgs/nixos> { configuration = ./config1.nix; }'
nixos-diff .#nixosConfigurations.machine1 .#nixosConfigurations.machine2
nixos-diff .#nixosConfigurations.machine1nix-env -f. -i$ meson setup build
$ cd build
$ meson compile$ nix-build --no-out-link tests.nix
$ update-tests