message: copy tbb.dll in case this is needed on Windows
diff: @@ -32,6 +32,7 @@ endif
  @echo '--- Translating Stan model to C++ code ---'
  $(WINE) bin/stanc$(EXE) $(STANCFLAGS) --o=$(subst \,/,$@) $(subst \,/,$<)
  +TBB_FOUND=$(notdir $(shell where tbb2.dll))
  .PRECIOUS: %.hpp
  %$(EXE) : %.hpp $(CMDSTAN_MAIN_O) $(LIBSUNDIALS) $(MPI_TARGETS) $(TBB_TARGETS)
  @@ -39,6 +40,14 @@ endif
  @echo '--- Compiling, linking C++ code ---'
  $(COMPILE.cpp) $(CXXFLAGS_PROGRAM) -x c++ -o $(subst \,/,$*).o $(subst \,/,$<)
  $(LINK.cpp) $(subst \,/,$*.o) $(CMDSTAN_MAIN_O) $(LDLIBS) $(LIBSUNDIALS) $(MPI_TARGETS) $(TBB_TARGETS) $(subst \,/,$(OUTPUT_OPTION))
  +ifeq ($(OS),Windows_NT)
  +ifneq ($(notdir $(shell where tbb.dll)),tbb.dll)
  + @echo 'WARNING: Intel TBB is not in PATH. Consider calling '
  + @echo 'make install-tbb'
  + @echo 'to avoid copying Intel TBB library files.'
  + cp -v $(TBB_TARGETS) $(@D)
  +endif
  +endif
  ##
  # Dependencies file
  