RuntimeError: No such operator torchvision::nms

Similar to #1405, but I’m seeing this issue in the nightly builds.

What I did:

I download two nightly wheels from https://download.pytorch.org/whl/nightly/cu100/torch_nightly.html, and installed them with:

pip install torch-1.4.0.dev20191017+cu100-cp37-cp37m-linux_x86_64.whl torchvision-0.5.0.dev20191017+cu100-cp37-cp37m-linux_x86_64.whl 

Then, I recompile detectron2; Running a simple detectron2 evaluation raises this error:

python tools/train_net.py --config-file configs/LVIS-InstanceSegmentation/mask_rcnn_R_101_FPN_1x.yaml --num-gpus 2 --eval-only DATALOADER.NUM_WORKERS 1 MODEL.WEIGHTS ~/data/D2models/LVIS-InstanceSegmentation/mask_rcnn_R_101_FPN_1x/144219035/model_final_824ab5.pkl

an example stack trace:

Traceback (most recent call last):
  File "tools/train_net.py", line 162, in <module>
    args=(args,),
  File "/private/home/yuxinwu/detectron2/detectron2/engine/launch.py", line 52, in launch
    main_func(*args)
  File "tools/train_net.py", line 133, in main
    res = Trainer.test(cfg, model)
  File "/private/home/yuxinwu/detectron2/detectron2/engine/defaults.py", line 413, in test
    results_i = inference_on_dataset(model, data_loader, evaluator)
  File "/private/home/yuxinwu/detectron2/detectron2/evaluation/evaluator.py", line 118, in inference_on_dataset
    outputs = model(inputs)
  File "/private/home/yuxinwu/miniconda3/lib/python3.7/site-packages/torch/nn/modules/module.py", line 541, in __call__
    result = self.forward(*input, **kwargs)
  File "/private/home/yuxinwu/detectron2/detectron2/modeling/meta_arch/rcnn.py", line 66, in forward
    return self.inference(batched_inputs)
  File "/private/home/yuxinwu/detectron2/detectron2/modeling/meta_arch/rcnn.py", line 119, in inference
    proposals, _ = self.proposal_generator(images, features, None)
  File "/private/home/yuxinwu/miniconda3/lib/python3.7/site-packages/torch/nn/modules/module.py", line 541, in __call__
    result = self.forward(*input, **kwargs)
  File "/private/home/yuxinwu/detectron2/detectron2/modeling/proposal_generator/rpn.py", line 179, in forward
    self.training,
  File "/private/home/yuxinwu/detectron2/detectron2/modeling/proposal_generator/rpn_outputs.py", line 136, in find_top_rpn_proposals
    keep = batched_nms(boxes.tensor, scores_per_img, lvl, nms_thresh)
  File "/private/home/yuxinwu/detectron2/detectron2/layers/nms.py", line 17, in batched_nms
    return box_ops.batched_nms(boxes, scores, idxs, iou_threshold)
  File "/private/home/yuxinwu/miniconda3/lib/python3.7/site-packages/torchvision/ops/boxes.py", line 70, in batched_nms
    keep = nms(boxes_for_nms, scores, iou_threshold)
  File "/private/home/yuxinwu/miniconda3/lib/python3.7/site-packages/torchvision/ops/boxes.py", line 31, in nms
    return torch.ops.torchvision.nms(boxes, scores, iou_threshold)
  File "/private/home/yuxinwu/miniconda3/lib/python3.7/site-packages/torch/_ops.py", line 61, in __getattr__
    op = torch._C._jit_get_operation(qualified_op_name)
RuntimeError: No such operator torchvision::nms

another stack trace: https://github.com/facebookresearch/detectron2/issues/94#issue-507812638

[fmassa]

Ok, I could reproduce the problem thanks to @pedrofreire snippet. It seems to be due to installing the package with python setup.py install, while I’ve always used python setup.py build develop in order to be able to modify the library without reinstalling it.

I’m looking into a fix

[dreiss]

Not right now (for OSS builds). We’ll look into it, but it is much easier to get a small app size if you’re able to bring all of the code into a single library.