import numpy, dpctl, dpctl.tensor as dpt

a = numpy.array([0, 1, 2])
numpy.diff(a, n=-1)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
Cell In[11], line 1
----> 1 numpy.diff(a, n=-1)

File ~/miniforge3/envs/dpnp_dev/lib/python3.11/site-packages/numpy/lib/function_base.py:1412, in diff(a, n, axis, prepend, append)
   1410     return a
   1411 if n < 0:
-> 1412     raise ValueError(
   1413         "order must be non-negative but got " + repr(n))
   1415 a = asanyarray(a)
   1416 nd = a.ndim

ValueError: order must be non-negative but got -1

# no exception raised by dpctl:
a = dpt.asarray(a)
dpt.diff(a, n=-1)
# Out: usm_ndarray([1, 1])