fixup

Author: PierreMarchand20

.github/workflows/CI.yml

@@ -174,8 +174,17 @@ jobs:
       - name: Generate coverage reports
         if: matrix.CODE_COVERAGE == 'ON'
         run: |
-          lcov --ignore-errors mismatch --capture --base-directory ./ --directory build/ --output-file coverage.info
-          lcov --remove  coverage.info '/usr/*' '*/hpddm/*' '*/pybind11/*' '*/lib/htool/*' --output-file  ../coverage.info
+          # Capture coverage: both MPI (.gcda in /tmp/gcov-mpi) and serial (.gcda in build/)
+          lcov --ignore-errors mismatch \
+               --capture \
+               --base-directory ./ \
+               --directory build \
+               --directory $COVDIR \
+               --output-file coverage.info
+
+          # Exclude third-party and system paths
+          lcov --remove coverage.info '/usr/*' '*/hpddm/*' '*/pybind11/*' '*/lib/htool/*' \
+               --output-file ../coverage.info
 
       - uses: actions/upload-artifact@v4
         with: