makefile - How to make GNU Make fail if a shell command assigned to a variable failed?

Question

I have a Make variable:

PASSWORD:=$(shell vault read -field=password test/password)

If vault is not installed, make will print make: vault: Command not found, but continue executing the recipe. How do I make it fail and stop execution if the expression fails?

Answer 1

Here is one approach:

$ cat err.mk
PASSWORD:=$(shell vault read -field=password test/password)
ifndef PASSWORD
$(error PASSWORD not set (maybe vault failed?))
endif
$ make -f err.mk
make: vault: Command not found
err.mk:3: *** PASSWORD not set (maybe vault failed?).  Stop.