Explicitly load GCC 15.2 when necessary

Author: knoepfel

.github/actions/configure-cmake/action.yaml

@@ -46,6 +46,13 @@ runs:
       run: |
         # Source the container entrypoint script
         . /entrypoint.sh
+
+        # Load Spack-installed GCC if necessary
+        if [ "$CPP_COMPILER" == "g++" ]
+          spack load gcc@15.2
+          CPP_COMPILER=$(which g++)
+        fi
+
         cd "$GITHUB_WORKSPACE/$BUILD_PATH"
         SOURCE_DIR="$GITHUB_WORKSPACE/$SOURCE_PATH"
         echo "Configuring with CMake preset: $PRESET"

.github/workflows/cmake-build.yaml

@@ -217,7 +217,7 @@ jobs:
 
     - name: Configure CMake
       id: configure
-      uses: Framework-R-D/phlex/.github/actions/configure-cmake@main
+      uses: knoepfel/phlex/.github/actions/configure-cmake@cpp23-for-containers
       with:
         source-path: ${{ env.local_checkout_path }}
         build-path: ${{ env.local_build_path }}