message: create downloads directory.
diff: @@ -392,6 +392,11 @@ ALL_PROJECT_TARGETS :=
  ARDUINO_LIBRARY_TARGETS :=
  ARDUINO_LIBRARY_ZIPS :=
  +# The download scripts require that the downloads directory already exist for
  +# improved error checking. To accomodate that, we first create a downloads
  +# directory.
  +$(shell mkdir -p ${MAKEFILE_DIR}/downloads)
  +
  # Directly download the flatbuffers library.
  DOWNLOAD_RESULT := $(shell $(MAKEFILE_DIR)/flatbuffers_download.sh ${MAKEFILE_DIR}/downloads)
  ifneq ($(DOWNLOAD_RESULT), SUCCESS)
  