Test with multiple installs

.github/workflows/ci.yml

@@ -252,3 +252,33 @@ jobs:
         openfoam${{ matrix.openfoam-version }} -help
     - name: Regression test
       run: . $WM_DIR/scripts/AllwmakeParseArguments
+
+  multiple-installs:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+    - name: Set up OpenFOAM v2406
+      uses: ./
+      with:
+        openfoam-version: 2406
+    - name: Set up OpenFOAM v2312
+      uses: ./
+      with:
+        openfoam-version: 2312
+    - name: Set up OpenFOAM 12
+      uses: ./
+      with:
+        openfoam-version: 12
+    - name: Test OpenFOAM 12
+      run: |
+        [ $WM_PROJECT_VERSION -eq 12 ]
+        icoFoam -help | grep OpenFOAM-12
+    - name: Test OpenFOAM 2312
+      run: |
+        [ $(openfoam -version) -eq 2312 ]
+        openfoam icoFoam -help | grep OpenFOAM-v2312
+    - name: Test OpenFOAM 2406
+      run: |
+        [ $(openfoam2406 -version) -eq 2406 ]
+        openfoam2406 icoFoam -help | grep OpenFOAM-v2406