一、问题描述

我的环境是Ubuntu20.04，Cuda版本是11.4，在复现OpenPCDet的时候遇到了下面问题：

Traceback (most recent call last):
  File "train.py", line 7, in <module>
    from test import repeat_eval_ckpt
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/test.py", line 14, in <module>
    from eval_utils import eval_utils
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/eval_utils/eval_utils.py", line 8, in <module>
    from pcdet.models import load_data_to_gpu
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/__init__.py", line 6, in <module>
    from .detectors import build_detector
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/detectors/__init__.py", line 1, in <module>
    from .detector3d_template import Detector3DTemplate
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/detectors/detector3d_template.py", line 8, in <module>
    from .. import backbones_2d, backbones_3d, dense_heads, roi_heads
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/backbones_3d/__init__.py", line 2, in <module>
    from .spconv_backbone import VoxelBackBone8x, VoxelResBackBone8x
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/backbones_3d/spconv_backbone.py", line 6, in <module>
    import spconv.pytorch as spconv
  File "/home/user/anaconda3/envs/openmmlab/lib/python3.8/site-packages/spconv/pytorch/__init__.py", line 7, in <module>
    from spconv.pytorch.core import SparseConvTensor
  File "/home/user/anaconda3/envs/openmmlab/lib/python3.8/site-packages/spconv/pytorch/core.py", line 21, in <module>
    from spconv.tools import CUDAKernelTimer
  File "/home/user/anaconda3/envs/openmmlab/lib/python3.8/site-packages/spconv/tools.py", line 16, in <module>
    from spconv.cppconstants import CPU_ONLY_BUILD
  File "/home/user/anaconda3/envs/openmmlab/lib/python3.8/site-packages/spconv/cppconstants.py", line 15, in <module>
    import spconv.core_cc as _ext
ImportError: generic_type: cannot initialize type "ExternalAllocator": an object with that name is already defined

其中，最关键的是ImportError: generic_type: cannot initialize type "ExternalAllocator": an object with that name is already defined

二、问题解决

pip uninstall spconv-cu114

如果不知道自己安装的哪个版本，可以通过：

pip list | grep spconv

获得：

然后安装：

pip install spconv-cu102

不过还可能遇到AttributeError: module 'spconv' has no attribute 'SparseModule'：

Traceback (most recent call last):
  File "train.py", line 7, in <module>
    from test import repeat_eval_ckpt
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/test.py", line 14, in <module>
    from eval_utils import eval_utils
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/eval_utils/eval_utils.py", line 8, in <module>
    from pcdet.models import load_data_to_gpu
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/__init__.py", line 6, in <module>
    from .detectors import build_detector
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/detectors/__init__.py", line 1, in <module>
    from .detector3d_template import Detector3DTemplate
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/detectors/detector3d_template.py", line 8, in <module>
    from .. import backbones_2d, backbones_3d, dense_heads, roi_heads
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/backbones_3d/__init__.py", line 2, in <module>
    from .spconv_backbone import VoxelBackBone8x, VoxelResBackBone8x
  File "/mnt/2206b677-3750-478c-b7c0-489c4f8ede41/cjy/OpenPCDet/tools/../pcdet/models/backbones_3d/spconv_backbone.py", line 31, in <module>
    class SparseBasicBlock(spconv.SparseModule):
AttributeError: module 'spconv' has no attribute 'SparseModule'

只要将pcdet/models/backbones_3d/spconv_backbone.py中

import spconv

修改为：

import spconv.pytorch as spconv

就可以正常运行了！