> The automatic conversion of 'u' to 'I' or 'L' causes test_buffer
> (PEP-3118 repo) to fail:
>
>
> # Not implemented formats. Ugly, but inevitable. This is the same as
> # issue #2531: equality is also used for membership testing and must
> # return a result.
> a = array.array('u', 'xyz')
> v = memoryview(a)
> self.assertNotEqual(v, a)
> self.assertNotEqual(a, v)

I don't understand: a buffer format is a format for the struct module, 
or for the array module?