Makefile special variable .DEFAULT_GOAL with assignment is null

.DEFAULT_GOAL=${IMG}  ${warning ${.DEFAULT_GOAL}}    BUILD_DIR=build    IMG=${BUILD_DIR}/hd60M.img  

When I print the value of .DEFAULT_GOAL, I get

Makefile:3:   make: *** No rule to make target `${IMG}'.  Stop.  

.DEFAULT_GOAL is null, why?

https://stackoverflow.com/questions/66021108/makefile-special-variable-default-goal-with-assignment-is-null February 03, 2021 at 12:04PM