1 test1: 2 touch -t 197101010000 foo 3 touch bar 4 5 # Note order-only dependency will not appear in $^ 6 test2: foo | bar 7 echo PASS_$^ 8 9 # bar is newer than foo but we should not rebuild it. 10 foo: | bar baz 11 12 baz: 13 touch $@ 14