space:= $(empty) $(empty)
comma:=,
merge=$(subst $(space),,$(1))
-confvar=$(call merge,$(foreach v,$(1),$(if $($(v)),y,n)))
+confvar=$(shell echo '$(foreach v,$(1),$(v)=$(subst ','\'',$($(v))))' | $(STAGING_DIR_HOST)/bin/mkhash md5)
strip_last=$(patsubst %.$(lastword $(subst .,$(space),$(1))),%,$(1))
paren_left = (