try to fix PR

Author: mcbarton

.github/actions/Build_and_Test_CppInterOp/action.yml

@@ -56,7 +56,8 @@ runs:
           cmake --build . --target sphinx-cppinterop --parallel ${{ env.ncpus }}
         else
           cmake --build . --target check-cppinterop --parallel ${{ env.ncpus }}
-          if [[ "${{ matrix.os }}" == "macos"* ]]; then
+          os="${{ matrix.os }}"
+          if [[ "${os}" == "macos"* ]]; then
             valgrind --show-error-list=yes --track-origins=yes --error-exitcode=1 unittests/CppInterOp/CppInterOpTests/unittests/bin/${{ env.BUILD_TYPE }}/CppInterOpTests
           endif
         fi
@@ -65,6 +66,7 @@ runs:
         echo "CPPINTEROP_DIR=$CPPINTEROP_DIR" >> $GITHUB_ENV
         echo "LLVM_BUILD_DIR=$LLVM_BUILD_DIR" >> $GITHUB_ENV
         echo "CPLUS_INCLUDE_PATH=$CPLUS_INCLUDE_PATH" >> $GITHUB_ENV
+
     - name: Build and Test/Install CppInterOp on Windows systems
       if: runner.os == 'Windows'
       shell: powershell