Error while running image_demo.py

I tried to run the demo in colab after following the install.md guide i successfully build iterdet but got a runtime error when tried to image_demo.py

Reproduction

python demo/image_demo.py demo/demo.jpg configs/iterdet/crowd_human_visible_faster_rcnn_r50_fpn_2x.py \
    crowd_human_visible_faster_rcnn_r50_fpn_2x.pth --device gpu

Environment python mmdet/utils/collect_env.py also gives the same error

Traceback (most recent call last):
  File "mmdet/utils/collect_env.py", line 62, in <module>
    for name, val in collect_env().items():
  File "mmdet/utils/collect_env.py", line 55, in collect_env
    from mmdet.ops import get_compiler_version, get_compiling_cuda_version
  File "/content/iterdet/mmdet/ops/__init__.py", line 2, in <module>
    from .conv_ws import ConvWS2d, conv_ws_2d
  File "/content/iterdet/mmdet/ops/conv_ws.py", line 23, in <module>
    class ConvWS2d(nn.Conv2d):
  File "/usr/local/lib/python3.6/dist-packages/mmcv/utils/registry.py", line 122, in _register
    module_class=cls, module_name=name, force=force)
  File "/usr/local/lib/python3.6/dist-packages/mmcv/utils/registry.py", line 58, in _register_module
    raise KeyError(f'{module_name} is already registered '
KeyError: 'ConvWS is already registered in conv layer'

torch==1.5.1+cu101
torchvision==0.6.1+cu101
mmdet==2.0.0+1531b8d
mmcv==1.0.4

nvcc --version

nvcc: NVIDIA (R) Cuda compiler driver
Copyright (c) 2005-2019 NVIDIA Corporation
Built on Sun_Jul_28_19:07:16_PDT_2019
Cuda compilation tools, release 10.1, V10.1.243

gcc --version

gcc (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0
Copyright (C) 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.

Error traceback

Traceback (most recent call last):
  File "demo/image_demo.py", line 3, in <module>
    from mmdet.apis import inference_detector, init_detector, show_result_pyplot
  File "/content/iterdet/mmdet/apis/__init__.py", line 1, in <module>
    from .inference import (async_inference_detector, inference_detector,
  File "/content/iterdet/mmdet/apis/inference.py", line 9, in <module>
    from mmdet.core import get_classes
  File "/content/iterdet/mmdet/core/__init__.py", line 5, in <module>
    from .mask import *  # noqa: F401, F403
  File "/content/iterdet/mmdet/core/mask/__init__.py", line 2, in <module>
    from .structures import BitmapMasks, PolygonMasks
  File "/content/iterdet/mmdet/core/mask/structures.py", line 8, in <module>
    from mmdet.ops.roi_align import roi_align
  File "/content/iterdet/mmdet/ops/__init__.py", line 2, in <module>
    from .conv_ws import ConvWS2d, conv_ws_2d
  File "/content/iterdet/mmdet/ops/conv_ws.py", line 23, in <module>
    class ConvWS2d(nn.Conv2d):
  File "/usr/local/lib/python3.6/dist-packages/mmcv/utils/registry.py", line 122, in _register
    module_class=cls, module_name=name, force=force)
  File "/usr/local/lib/python3.6/dist-packages/mmcv/utils/registry.py", line 58, in _register_module
    raise KeyError(f'{module_name} is already registered '
KeyError: 'ConvWS is already registered in conv layer'

[filaPro]

Fixed in b293300.

[Udit1999]

Hi @filaPro Thanks for your help. The issue is fixed by downgrading mmcv to 0.5.1.