-# We have to do this mangling using the shell, because words may contain
-# spaces and GNU make doesn't have any quoting interpretation.
-ifneq ($$(strip $$($1_$2_DEP_INCLUDE_DIRS)),)
-$1_$2_CC_INC_FLAGS:=$$(shell for i in $$($1_$2_DEP_INCLUDE_DIRS); do echo $$($1_$2_DEP_INCLUDE_DIRS_FLAG)\"$$$$i\"; done)
+ifneq ($$(strip $$($1_$2_DEP_INCLUDE_DIRS_SINGLE_QUOTED)),)
+$1_$2_CC_INC_FLAGS := $$(subst $$(space)',$$(space)$$($1_$2_DEP_INCLUDE_DIRS_FLAG)',$$(space)$$($1_$2_DEP_INCLUDE_DIRS_SINGLE_QUOTED))