message: Add ex18.hpp dependency for ex18p.cpp only when MFEM_USE_MPI=YES
diff: @@ -38,7 +38,10 @@ endif
  %: %.cpp
  # Additional dependencies
  -ex18 ex18p: ex18.hpp
  +ex18: ex18.hpp
  +ifeq ($(MFEM_USE_MPI),YES)
  +ex18p: ex18.hpp
  +endif
  # Replace the default implicit rule for *.cpp files
  %: $(SRC)%.cpp $(MFEM_LIB_FILE) $(CONFIG_MK)
  