explicitly point to compiler (for windows)

Author: toroidal-code

.github/workflows/test.yml

@@ -28,15 +28,27 @@ jobs:
     - name: Install CMake
       uses: lukka/get-cmake@latest
 
-    - name: Install LLVM and Clang
+    - name: Install LLVM and Clang 17
       uses: KyleMayes/install-llvm-action@v1
       with:
-        version: "15"
-        env: ${{ matrix.compiler == 'llvm' }}
-      if: ${{ matrix.compiler == 'llvm' }}
+        version: "17"
+        env: true
+      if: ${{ matrix.compiler == 'llvm' && matrix.os != 'macos-latest' }}
 
-    - name: Configure  
-      run: cmake -Bbuild -DBUILD_TESTS=YES
+    - name: Install LLVM and Clang 15
+      uses: KyleMayes/install-llvm-action@v1
+      with:
+        version: "15.0.7"
+        env: true
+      if: ${{ matrix.compiler == 'llvm' && matrix.os == 'macos-latest' }}
+
+    - name: Configure for native compiler
+      run: cmake -B build -DBUILD_TESTS=YES
+      if: ${{ matrix.compiler == 'native'}}
+
+    - name: Configure for non-native compiler
+      run: cmake -B build -G Ninja -DBUILD_TESTS=YES -DCMAKE_C_COMPILER="$CC" -DCMAKE_CXX_COMPILER="$CXX"
+      if: ${{ matrix.compiler != 'native'}}
 
     - name: Build
       run: cmake --build build --config Release