OSError: /usr/local/lib/python3.7/dist-packages/torchtext/_torchtext.so: undefined symbol: _ZNK3c10

说明：在Colab上跑模型报错，其中torch版本1.7。

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运行截图：

报错信息如下：

Traceback (most recent call last):
  File "tools/train_csc.py", line 11, in <module>
    from pytorch_lightning.callbacks import ModelCheckpoint
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/__init__.py", line 60, in <module>
    from pytorch_lightning import metrics
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/metrics/__init__.py", line 14, in <module>
    from pytorch_lightning.metrics.metric import Metric
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/metrics/metric.py", line 23, in <module>
    from pytorch_lightning.metrics.utils import _flatten, dim_zero_cat, dim_zero_mean, dim_zero_sum
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/metrics/utils.py", line 18, in <module>
    from pytorch_lightning.utilities import rank_zero_warn
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/utilities/__init__.py", line 24, in <module>
    from pytorch_lightning.utilities.apply_func import move_data_to_device
  File "/usr/local/lib/python3.7/dist-packages/pytorch_lightning/utilities/apply_func.py", line 25, in <module>
    from torchtext.data import Batch
  File "/usr/local/lib/python3.7/dist-packages/torchtext/__init__.py", line 40, in <module>
    _init_extension()
  File "/usr/local/lib/python3.7/dist-packages/torchtext/__init__.py", line 36, in _init_extension
    torch.ops.load_library(ext_specs.origin)
  File "/usr/local/lib/python3.7/dist-packages/torch/_ops.py", line 104, in load_library
    ctypes.CDLL(path)
  File "/usr/lib/python3.7/ctypes/__init__.py", line 364, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: /usr/local/lib/python3.7/dist-packages/torchtext/_torchtext.so: undefined symbol: _ZNK3c104Type14isSubtypeOfExtESt10shared_ptrIS0_EPSo

解决：

关键信息： OSError: /usr/local/lib/python3.7/dist-packages/torchtext/_torchtext.so: undefined symbol: _ZNK3c104Type14isSubtypeOfExtESt10shared_ptrIS0_EPSo

解释： torchtext的问题，优先考虑是不是版本不对应的问题。

1. 查找torch1.7对应torchtext版本

参考torchtext版本兼容官网repo：https://github.com/pytorch/text/

2. 安装torchtext

pip install torchtext==0.8

3. 重启kernel

参考资料：

pytorch 中 torchtext 遇到问题_torchtext.so undefined symbol解决方法(亲测有效)_阿正的梦工坊的博客-CSDN博客