Casting a dtype that includes a subarray to an object will now ensure a copy of the subarray. Previously an unsafe view was returned:
arr = np.ones(3, dtype=[("f", "i", 3)])
subarray_fields = arr.astype(object)[0]
subarray = subarray_fields[0] # "f" field
np.may_share_memory(subarray, arr)
Is now always false. While previously it was true for the specific cast.