Add github CI

.github/workflows/ci.yml

@@ -0,0 +1,25 @@
+name: "Build & Test (nix)"
+
+# FIXME: This build is too large and runs out of space
+# on github runners.
+# on:
+#   pull_request:
+#   push:
+#     branches:
+#       - master
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Nix
+      uses: DeterminateSystems/nix-installer-action@main
+    - name: Run the Magic Nix Cache
+      uses: DeterminateSystems/magic-nix-cache-action@main
+    - name: Check
+      run: |
+        nix flake check

flake.nix

@@ -132,5 +132,26 @@
         ];
       };
     };
+
+    nixosMachines = forAllSystems (
+      system: let
+        # Filter the configurations to those that match the current system
+        matchingSystemConfigurations = nixpkgs.lib.filterAttrs (_: c: c.pkgs.system == system) self.nixosConfigurations;
+
+        # Map each matching configuration to its top-level system derivation
+        toplevelDerivations = nixpkgs.lib.mapAttrs (_: c: c.config.system.build.toplevel) matchingSystemConfigurations;
+      in
+        toplevelDerivations
+    );
+
+    checks =
+      forAllSystems (
+        system:
+          {
+          }
+          # Add all our homemanager configurations
+          // (nixpkgs.lib.mapAttrs (_: c: c.activationPackage) (nixpkgs.lib.filterAttrs (_: c: c.pkgs.system == system) self.homeConfigurations))
+      )
+      // self.nixosMachines;
   };
 }