How do I get $(error …) to work conditionally in GNU Make?

Question

I\'d like to use $(error ...) to abort my make process if certain preconditions aren\'t met. The fails_to_work target should abort when failing t

Answer 1

You're trying to get the shell stuff in a recipe to conditionally invoke makefile stuff, which doesn't work, as you've found.

I can think of two options:

1. Simply remove the $(error) stuff. If test fails, then it will return a non-zero exit status, and the Make process will terminate at that point.

2. Take the test out of the rule, and use a Make conditional (which in turn invokes shell functionality), e.g.:

   ifeq ($(shell test -d /foobar; echo $$?),1)
   $(error Not a directory)
   endif