ci: test with Xcode 27

.github/workflows/test.yml

@@ -102,6 +102,7 @@ jobs:
       - build-nix
       # - build-nix-macos
       - build-macos
+      - build-macos-xcode-27
       - build-macos-freetype
       - build-snap
       - test
@@ -1109,6 +1110,46 @@ jobs:
             COMPILATION_CACHE_CAS_PATH=/Users/runner/Library/Developer/Xcode/DerivedData/CompilationCache.noindex \
             COMPILATION_CACHE_KEEP_CAS_DIRECTORY=YES
 
+  build-macos-xcode-27:
+    runs-on: namespace-profile-ghostty-macos-tahoe
+    needs: test
+    env:
+      ZIG_LOCAL_CACHE_DIR: /Users/runner/zig/local-cache
+      ZIG_GLOBAL_CACHE_DIR: /Users/runner/zig/global-cache
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+
+      - name: Setup Cache
+        uses: namespacelabs/nscloud-cache-action@c5f8dab7560444c4bf8dbc64f1b203431873c547 # v1.6.1
+        with:
+          cache: |
+            xcode
+          path: |
+            /Users/runner/zig
+
+      # TODO(tahoe): https://github.com/NixOS/nix/issues/13342
+      - uses: DeterminateSystems/nix-installer-action@main
+        with:
+          determinate: true
+      - uses: cachix/cachix-action@5f2d7c5294214f71b873db4b969586b980625e71 # v17
+        with:
+          name: ghostty
+          authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
+
+      - name: Xcode Select
+        run: sudo xcode-select -s /Applications/Xcode_27.app
+
+      - name: Xcode Version
+        run: xcodebuild -version
+
+      - name: get the Zig deps
+        id: deps
+        run: nix build -L .#deps && echo "deps=$(readlink ./result)" >> $GITHUB_OUTPUT
+
+      - name: Build with Xcode 27
+        run: nix develop -c zig build --system ${{ steps.deps.outputs.deps }} -Demit-macos-app=false
+
   build-macos-freetype:
     runs-on: namespace-profile-ghostty-macos-tahoe
     needs: test