message: fixing makefile (issue
diff: ifeq ($(CMDSTAN_SUBMODULES),1)
  +bin/cmdstan/stansummary.o : src/cmdstan/stansummary_helper.hpp
  bin/cmdstan/%.o : src/cmdstan/%.cpp
  @mkdir -p $(dir $@)
  - $(COMPILE.cpp) $(OUTPUT_OPTION) $<
  + $(COMPILE.cpp) -fvisibility=hidden $(OUTPUT_OPTION) $<
  ifeq ($(OS),Windows_NT)
  # bitness check to decide which program_options .a file to select
  