inform:
	@echo
ifneq ($(CFG),release)
ifneq ($(CFG),debug)
	@echo "Invalid configuration "$(CFG)" specified."
	@echo -n "You must specify a configuration when "
	@echo "running make, e.g. make CFG=debug"
	@echo
	@echo -n "Possible choices for configuration are "
	@echo "'release' and 'debug'"
	@exit 1
endif
endif