array_iter_impl -> HPySeqIter_New -> look up __iter__ and call it -> array_iter_impl.

You can hit this by doing np.range(10).__iter__(). This was added in 3a7a0d2.

For some reason calling src_cycle = cycle(self.pool) in setting up the random.bit_generator is hitting this in PyPy but not in CPython. Maybe cycle is implemented slightly differently in CPython, and avoids calling self.pool.__iter__().