how about as a module

.github/workflows/build-machines-and-homes.yml

@@ -68,7 +68,8 @@ jobs:
           # always save the cache
           save-always: true
       # - run: nix build -L .#nixosConfigurations.${{ matrix.machine }}.config.system.build.toplevel
-      - run: nix run -L github:nix-community/nixos-generators -- --flake .#pancake -f sd-aarch64 --system aarch64-linux
+      # - run: nix run -L github:nix-community/nixos-generators -- --flake .#pancake -f sd-aarch64 --system aarch64-linux
+      - run: nix build -L .#nixosConfigurations.pancake.config.formats.sd-aarch64
   build-homes:
     strategy:
       matrix:

flake.lock

@@ -899,6 +899,40 @@
         "type": "github"
       }
     },
+    "nixlib": {
+      "locked": {
+        "lastModified": 1736643958,
+        "narHash": "sha256-tmpqTSWVRJVhpvfSN9KXBvKEXplrwKnSZNAoNPf/S/s=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "1418bc28a52126761c02dd3d89b2d8ca0f521181",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "nixos-generators": {
+      "inputs": {
+        "nixlib": "nixlib",
+        "nixpkgs": "nixpkgs_5"
+      },
+      "locked": {
+        "lastModified": 1737057290,
+        "narHash": "sha256-3Pe0yKlCc7EOeq1X/aJVDH0CtNL+tIBm49vpepwL1MQ=",
+        "owner": "nix-community",
+        "repo": "nixos-generators",
+        "rev": "d002ce9b6e7eb467cd1c6bb9aef9c35d191b5453",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixos-generators",
+        "type": "github"
+      }
+    },
     "nixos-hardware": {
       "locked": {
         "lastModified": 1737590910,
@@ -1075,6 +1109,22 @@
       }
     },
     "nixpkgs_5": {
+      "locked": {
+        "lastModified": 1736657626,
+        "narHash": "sha256-FWlPMUzp0lkQBdhKlPqtQdqmp+/C+1MBiEytaYfrCTY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2f9e2f85cb14a46410a1399aa9ea7ecf433e422e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_6": {
       "locked": {
         "lastModified": 1737569578,
         "narHash": "sha256-6qY0pk2QmUtBT9Mywdvif0i/CLVgpCjMUn6g9vB+f3M=",
@@ -1238,8 +1288,9 @@
         "lix": "lix",
         "lix-module": "lix-module",
         "niri": "niri",
+        "nixos-generators": "nixos-generators",
         "nixos-hardware": "nixos-hardware",
-        "nixpkgs": "nixpkgs_5",
+        "nixpkgs": "nixpkgs_6",
         "nixpkgs-garage": "nixpkgs-garage",
         "nixpkgs-rpi": "nixpkgs-rpi",
         "nixvim": "nixvim",

flake.nix

@@ -70,6 +70,7 @@
     };
     nixos-hardware.url = "github:nixos/nixos-hardware";
     nixpkgs-rpi.url = "github:nixos/nixpkgs/d4e529a24b66b0341f2b866c5abe3ad8a96be2d7";
+    nixos-generators.url = "github:nix-community/nixos-generators";
 
     nixpkgs-garage.url = "github:cything/nixpkgs/garage-module"; # unmerged PR
 
@@ -212,6 +213,7 @@
                       nixpkgs.pkgs = pkgsFor "aarch64-linux";
                     }
                     inputs.nixos-hardware.nixosModules.raspberry-pi-3
+                    inputs.nixos-generators.nixosModules.all-formats
                     ./hosts/pancake
                     ./modules
                   ];