Update nix build command

.gitea/workflows/build.yml

@@ -28,8 +28,10 @@ jobs:
           git remote -v 2>&1 || true
           test -f flake.nix && echo "flake.nix present" || echo "NO flake.nix"
 
+      # checks is keyed per-system (checks.<system>.default); nix build's
+      # #attr shorthand can't resolve it, so resolve the current system inline.
       - name: Build + offline test suite
-        run: nix build -L .#checks.default
+        run: nix build -L ".#checks.$(nix eval --impure --raw --expr 'builtins.currentSystem').default"
 
       - name: Live portal tests
         if: ${{ secrets.RW_LIVE_API_KEY != '' }}

AGENTS.md

@@ -201,8 +201,10 @@ cached.
 - Build needs SDL3 + SDL3_ttf/image/mixer/net + GTest installed; CI uses
   Gitea Actions on a self-hosted host runner (`build-server`, no docker).
   The workflow lives in `.gitea/workflows/build.yml` and runs on both `dev`
-  and `main`. It runs `nix build -L .#checks.default` (build + the offline
+  and `main`. It runs `nix build -L .#checks.<system>.default` (build + the
-  test suite); when the `RW_LIVE_API_KEY` secret is set it also runs
+  offline test suite; `checks` is keyed per-system, so the workflow resolves
+  the current system via `nix eval --impure --expr 'builtins.currentSystem'`);
+  when the `RW_LIVE_API_KEY` secret is set it also runs
   `test_api_client` / `test_license_service` against the portal via
   `nix develop` (outside the sandbox, like a dev machine).
 - `test_assets` must pass before committing — it catches missing fonts/images