Test whether a directory exists inside a makefile

Question

In his answer @Grundlefleck explains how to check whether a directory exists or not. I tried some to use this inside a makefile as follow:

foo.b         


        

Answer 1

This approach functions with minimal echos:

.PHONY: all
all:
ifneq ($(wildcard ~/Dropbox/.*),)
        @echo "Found ~/Dropbox."
else
        @echo "Did not find ~/Dropbox."
endif