Gradient become Nan for 0 value test

[Yuhang-7]

The following code is not working:
def loss(x):
return np.linalg.norm(x) ** 2

x = np.zeros([3])
a = grad(loss)(x)
print(a)

Error Message:

/Users/.local/lib/python3.6/site-packages/autograd/numpy/linalg.py:100: RuntimeWarning: invalid value encountered in double_scalars
return expand(g / ans) * x
array([nan, nan, nan])

[hlee13]

def loss(x):
# return np.linalg.norm(x) ** 2
return np.dot(x, x)