How to export variables from makefile rule?
Solution 1:
In general, variables do not pass from one rule to another. But there is a way to do this with target-specific variables:
another_rule: DB_USER=XXX
another_rule: DB_PASS=YYY
another_rule:
@echo user is ${DB_USER}
@echo pass is $(DB_PASS)
If writing so many extra lines for every rule is too tedious, you can wrap them in a function:
define db_env
$(1): DB_USER=XXX
$(1): DB_PASS=YYY
endef
$(eval $(call db_env,another_rule))
another_rule:
@echo user is ${DB_USER}
@echo pass is $(DB_PASS)