'Ensure that concrete specs are matched *exactly* by hash.'

def test_satisfies_same_spec_with_different_hash(self):

    s1 = Spec('mpileaks').concretized()
    s2 = s1.copy()
    assert s1.satisfies(s2)
    assert s2.satisfies(s1)
    s2._hash = s1.dag_hash()[(-1)::(-1)]
    assert (not s1.satisfies(s2))
    assert (not s2.satisfies(s1))
