echo 在 Makefile 中不起作用

Question

I have added code to Makefile something like:

ifeq "$var" "1"
    var_1 := 1\
    echo "g++ version OK"\
    $(info $(var_1))
else
    echo "needs to be updated"
endif

I am using tabs everywhere in this part of code. It does not seem to work, nothing echoes at all when I run make, Makefile already contains the object files and flags etc. Does it have something to with the position of the code? I'm unable to identify. Please help.

Answer 1

echo is a shell command, it only works from within a recipe or $(shell ...) function.

Anywhere else use $(info ...) function.