dataloader .__del__ 报错

以下的讨论是基于:
MXNet版本: Name: mxnet-cu102, Version: 1.7.0
操作系统: Ubuntu 18.04.5 LTS

我按着教程写的MLP的Gluon实现中,train_ch3可以正常训练

epoch 1, loss 2.3002, train acc 0.130, test acc 0.234 epoch 2, loss 1.4773, train acc 0.415, test acc 0.587 epoch 3, loss 0.9385, train acc 0.639, test acc 0.719

但之后会报错

Exception ignored in: <function DataLoader.__del__ at 0x7fca63a51e50> Traceback (most recent call last): File "/home/liuchaoyi/miniconda3/envs/gluon/lib/python3.8/site-packages/mxnet/gluon/data/dataloader.py", line 656, in __del__ AttributeError: 'NoneType' object has no attribute 'Pool' Exception ignored in: <function Pool.__del__ at 0x7fca63a481f0> Traceback (most recent call last): File "/home/liuchaoyi/miniconda3/envs/gluon/lib/python3.8/multiprocessing/pool.py", line 268, in __del__ File "/home/liuchaoyi/miniconda3/envs/gluon/lib/python3.8/multiprocessing/queues.py", line 362, in put AttributeError: 'NoneType' object has no attribute 'dumps'

小白现在蒙蒙的。求各路大神的帮助,谢谢。