am 9db1fc2b: am b392641d: Make  fail if it\'s called after including

Merge commit '9db1fc2bea0b75b59ad52f94faa1e7d66209d2d2'

* commit '9db1fc2bea0b75b59ad52f94faa1e7d66209d2d2':
  Make $(my-dir) fail if it's called after including $(CLEAR_VARS)