MMDet Tutorial not working on Colab

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Checklist

1. I have searched related issues but cannot get the expected help.
2. I have read the FAQ documentation but cannot get the expected help.
3. The bug has not been fixed in the latest version.

Describe the bug MMDet Tutorial no working on Colab.

Reproduction

1. What command or script did you run?

Followed the link to open the tutorial on Colab. Then tried to run the cells starting from the top. However, the cell that is checking mmcv installation fails with error:

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-2-fad1b02c85b9> in <module>()
      8 
      9 # Check mmcv installation
---> 10 from mmcv.ops import get_compiling_cuda_version
     11 print(get_compiling_cuda_version())
     12 print(get_compiler_version())

3 frames
/usr/lib/python3.7/importlib/__init__.py in import_module(name, package)
    125                 break
    126             level += 1
--> 127     return _bootstrap._gcd_import(name[level:], package, level)
    128 
    129 

ImportError: /usr/local/lib/python3.7/dist-packages/mmcv/_ext.cpython-37m-x86_64-linux-gnu.so: undefined symbol: _Z27points_in_boxes_cpu_forwardN2at6TensorES0_S0_
---------------------------------------------------------------------------

1. Did you make any modifications on the code or config? Did you understand what you have modified?

The issue might be related with Colab using now CUDA 11.1. Tried to use:

!pip install -U torch==1.8.1+cu111 torchvision==0.9.1+cu111 -f https://download.pytorch.org/whl/torch_stable.html

However, this didn’t solve the issue.

1. What dataset did you use?

None

Environment

nvcc: NVIDIA ® Cuda compiler driver Copyright © 2005-2020 NVIDIA Corporation Built on Mon_Oct_12_20:09:46_PDT_2020 Cuda compilation tools, release 11.1, V11.1.105 Build cuda_11.1.TC455_06.29190527_0 gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0 Copyright © 2017 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[annie2008hi]

I met the issue: ImportError: /home/anaconda3/envs/mmseg/lib/python3.6/site-packages/mmcv/_ext.cpython-36m-x86_64-linux-gnu.so: undefined symbol: Z27points_in_boxes_cpu_forwardN2at6TensorES0_S0

I change the version of mmcv-full to 1.3.13, by following command pip install mmcv-full==1.3.13 -f https://download.openmmlab.com/mmcv/dist/{CUDA_VERSION}/{PYTORCH_VERSION}/index.html It solves my problem.

[withbrightmoon]

@Hihien Have you solve this problem? I also meet it when training faster rcnn / mask rcnn models on coco / cityscapes datasets.