The code around copying into and out of variable-sized dimensions in DyND Python is a bit fragile, and it broke with a very recent change to memory_block_data. See the commented out tests at https://github.com/libdynd/dynd-python/blob/master/dynd/tests/test_dtype_datashape.py#L43 and https://github.com/libdynd/dynd-python/blob/master/dynd/tests/test_array_squeeze.py#L22.