No module named 'mmcv._ext'

[yangdonghan50]

Checklist

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

Reproduction python tools/train.py ./configs/sem_fpn/fpn_r50_512x512_160k_ade20k.py

Environment sys.platform: linux Python: 3.7.7 (default, May 7 2020, 21:25:33) [GCC 7.3.0] CUDA available: True CUDA_HOME: /usr/local/cuda NVCC: Cuda compilation tools, release 10.1, V10.1.243 GPU 0,1,2,3: TITAN Xp GCC: gcc (Ubuntu 7.4.0-1ubuntu1~18.04.1) 7.4.0 PyTorch: 1.5.0 PyTorch compiling details: PyTorch built with:

• GCC 7.3
• C++ Version: 201402
• Intel(R) Math Kernel Library Version 2019.0.4 Product Build 20190411 for Intel(R) 64 architecture applications
• Intel(R) MKL-DNN v0.21.1 (Git Hash 7d2fd500bc78936d1d648ca713b901012f470dbc)
• OpenMP 201511 (a.k.a. OpenMP 4.5)
• NNPACK is enabled
• CPU capability usage: AVX2
• CUDA Runtime 10.1
• NVCC architecture flags: -gencode;arch=compute_37,code=sm_37;-gencode;arch=compute_50,code=sm_50;-gencode;arch=compute_60,code=sm_60;-gencode;arch=compute_61,code=sm_61;-gencode;arch=compute_70,code=sm_70;-gencode;arch=compute_75,code=sm_75;-gencode;arch=compute_37,code=compute_37
• CuDNN 7.6.3
• Magma 2.5.2
• Build settings: BLAS=MKL, BUILD_TYPE=Release, CXX_FLAGS= -Wno-deprecated -fvisibility-inlines-hidden -fopenmp -DNDEBUG -DUSE_FBGEMM -DUSE_QNNPACK -DUSE_PYTORCH_QNNPACK -DUSE_XNNPACK -DUSE_INTERNAL_THREADPOOL_IMPL -O2 -fPIC -Wno-narrowing -Wall -Wextra -Werror=return-type -Wno-missing-field-initializers -Wno-type-limits -Wno-array-bounds -Wno-unknown-pragmas -Wno-sign-compare -Wno-unused-parameter -Wno-unused-variable -Wno-unused-function -Wno-unused-result -Wno-strict-overflow -Wno-strict-aliasing -Wno-error=deprecated-declarations -Wno-stringop-overflow -Wno-error=pedantic -Wno-error=redundant-decls -Wno-error=old-style-cast -fdiagnostics-color=always -faligned-new -Wno-unused-but-set-variable -Wno-maybe-uninitialized -fno-math-errno -fno-trapping-math -Werror=format -Wno-stringop-overflow, PERF_WITH_AVX=1, PERF_WITH_AVX2=1, PERF_WITH_AVX512=1, USE_CUDA=ON, USE_EXCEPTION_PTR=1, USE_GFLAGS=OFF, USE_GLOG=OFF, USE_MKL=ON, USE_MKLDNN=ON, USE_MPI=OFF, USE_NCCL=ON, USE_NNPACK=ON, USE_OPENMP=ON, USE_STATIC_DISPATCH=OFF,

TorchVision: 0.6.0a0+82fd1c8 OpenCV: 4.3.0 MMCV: 1.1.2 MMSegmentation: 0.6.0+c3e4dbc MMCV Compiler: n/a MMCV CUDA Compiler: n/a

Error traceback Traceback (most recent call last): File "tools/train.py", line 13, in from mmseg.apis import set_random_seed, train_segmentor File "/home/user/workspace/mmsegmentation/mmseg/apis/init.py", line 1, in from .inference import inference_segmentor, init_segmentor, show_result_pyplot File "/home/user/workspace/mmsegmentation/mmseg/apis/inference.py", line 8, in from mmseg.models import build_segmentor File "/home/user/workspace/mmsegmentation/mmseg/models/init.py", line 1, in from .backbones import * # noqa: F401,F403 File "/home/user/workspace/mmsegmentation/mmseg/models/backbones/init.py", line 1, in from .fast_scnn import FastSCNN File "/home/user/workspace/mmsegmentation/mmseg/models/backbones/fast_scnn.py", line 6, in from mmseg.models.decode_heads.psp_head import PPM File "/home/user/workspace/mmsegmentation/mmseg/models/decode_heads/init.py", line 13, in from .point_head import PointHead File "/home/user/workspace/mmsegmentation/mmseg/models/decode_heads/point_head.py", line 6, in from mmcv.ops import point_sample File "/home/user/workspace/mmcv/mmcv/ops/init.py", line 1, in from .bbox import bbox_overlaps File "/home/user/workspace/mmcv/mmcv/ops/bbox.py", line 3, in ext_module = ext_loader.load_ext('_ext', ['bbox_overlaps']) File "/home/user/workspace/mmcv/mmcv/utils/ext_loader.py", line 10, in load_ext ext = importlib.import_module('mmcv.' + name) File "/home/user/workspace/yes/envs/open-mmlab/lib/python3.7/importlib/init.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) ModuleNotFoundError: No module named 'mmcv._ext'

[xvjiarui]

Hi @yangdonghan50 You need to install mmcv-full for extension ops.

[yangdonghan50]

@xvjiarui it works, thanks!

[Liusandian]

@xvjiarui it works, thanks!

did you mean use :pip install mmcv-full? or other instructions?

[yangdonghan50]

@Liusandian pip install mmcv-full

[neomukul]

@Liusandian @xvjiarui with mmcv-full it advise to downgrade the mmcv. any workaround???