Aborted (core dumped) in flow.Tensor

[deepliao]

Description

A crash is triggered when value is set to a negative value.

Code to reproduce bug

import oneflow as flow
import numpy as np

negative_number = -610428
x = flow.Tensor(negative_number)
digamma_result = x.digamma()
digamma_result.numpy()

output:

Stack trace (most recent call last) in thread 1538:
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f6510f5669f, in 
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f650977b957, in 
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f650977b157, in 
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f65097769e8, in vm::ThreadCtx::TryReceiveAndRun()
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f6509719134, in vm::EpStreamPolicyBase::Run(vm::Instruction*) const
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f650971c517, in vm::Instruction::Compute()
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f65097218d8, in vm::OpCallInstructionPolicy::Compute(vm::Instruction*)
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f6509721598, in 
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f650971e73a, in 
   Object "/opt/conda/lib/python3.8/site-packages/oneflow/../oneflow.libs/liboneflow-6efc1e6f.so", at 0x7f6500fbc00a, in 

Aborted (Signal sent by tkill() 1465 0)
Aborted (core dumped)