Our Colab Notebook has step-by-step instructions that install detectron2. The Dockerfile also installs detectron2 with a few simple commands.
- Linux or macOS with Python ≥ 3.6
- PyTorch ≥ 1.3
- torchvision that matches the PyTorch installation. You can install them together at pytorch.org to make sure of this.
- OpenCV, optional, needed by demo and visualization
- pycocotools:
pip install cython; pip install 'git+https://github.com/cocodataset/cocoapi.git#subdirectory=PythonAPI'
After having the above dependencies and gcc & g++ ≥ 4.9, run:
python -m pip install 'git+https://github.com/facebookresearch/detectron2.git'
# (add --user if you don't have permission)
# Or, to install it from a local clone:
git clone https://github.com/facebookresearch/detectron2.git
cd detectron2 && python -m pip install -e .
# Or if you are on macOS
# CC=clang CXX=clang++ python -m pip install -e .
To rebuild detectron2 that's built from a local clone, use rm -rf build/ **/*.so
to clean the
old build first. You often need to rebuild detectron2 after reinstalling PyTorch.
# for CUDA 10.1:
python -m pip install detectron2 -f https://dl.fbaipublicfiles.com/detectron2/wheels/cu101/index.html
You can replace cu101 with "cu{100,92}" or "cpu".
Note that:
- Such installation has to be used with the latest official PyTorch release (currently 1.4). It will not work with your custom build of PyTorch.
- Such installation is out-of-date w.r.t. master branch of detectron2. It may not be compatible with the master branch of a research project that uses detectron2 (e.g. those in projects or meshrcnn).
If you met issues using the pre-built detectron2, please uninstall it and try building it from source.
Click each issue for its solutions:
Undefined torch/aten/caffe2 symbols, or segmentation fault immediately when running the library.
This can happen if detectron2 or torchvision is not compiled with the version of PyTorch you're running.
If you use a pre-built torchvision, uninstall torchvision & pytorch, and reinstall them
following pytorch.org.
If you manually build detectron2 or torchvision, remove the files you built (build/
, **/*.so
)
and rebuild them.
If you cannot resolve the problem, please include the output of gdb -ex "r" -ex "bt" -ex "quit" --args python -m detectron2.utils.collect_env
in your issue.
Undefined C++ symbols in `detectron2/_C*.so`.
Usually it's because the library is compiled with a newer C++ compiler but run with an old C++ run time. This can happen with old anaconda.
Try conda update libgcc
. Then rebuild detectron2.
"Not compiled with GPU support" or "Detectron2 CUDA Compiler: not available".
CUDA is not found when building detectron2. You should make sure
python -c 'import torch; from torch.utils.cpp_extension import CUDA_HOME; print(torch.cuda.is_available(), CUDA_HOME)'
print valid outputs at the time you build detectron2.
"invalid device function" or "no kernel image is available for execution".
Two possibilities:
-
You build detectron2 with one version of CUDA but run it with a different version.
To check whether it is the case, use
python -m detectron2.utils.collect_env
to find out inconsistent CUDA versions. In the output of this command, you should expect "Detectron2 CUDA Compiler", "CUDA_HOME", "PyTorch built with - CUDA" to contain cuda libraries of the same version.When they are inconsistent, you need to either install a different build of PyTorch (or build by yourself) to match your local CUDA installation, or install a different version of CUDA to match PyTorch.
-
Detectron2 or PyTorch/torchvision is not built for the correct GPU architecture (compute compatibility).
The GPU architecture for PyTorch/detectron2/torchvision is available in the "architecture flags" in
python -m detectron2.utils.collect_env
.The GPU architecture flags of detectron2/torchvision by default matches the GPU model detected during building. This means the compiled code may not work on a different GPU model. To overwrite the GPU architecture for detectron2/torchvision, use
TORCH_CUDA_ARCH_LIST
environment variable during building.For example,
export TORCH_CUDA_ARCH_LIST=6.0,7.0
makes it work for both P100s and V100s. Visit developer.nvidia.com/cuda-gpus to find out the correct compute compatibility number for your device.
Undefined CUDA symbols or cannot open libcudart.so.
The version of NVCC you use to build detectron2 or torchvision does not match the version of CUDA you are running with. This often happens when using anaconda's CUDA runtime.
Use python -m detectron2.utils.collect_env
to find out inconsistent CUDA versions.
In the output of this command, you should expect "Detectron2 CUDA Compiler", "CUDA_HOME", "PyTorch built with - CUDA"
to contain cuda libraries of the same version.
When they are inconsistent, you need to either install a different build of PyTorch (or build by yourself) to match your local CUDA installation, or install a different version of CUDA to match PyTorch.
"ImportError: cannot import name '_C'".
Please build and install detectron2 following the instructions above.
ONNX conversion segfault after some "TraceWarning".
Build and install ONNX from its source code using a compiler whose version is closer to what's used by PyTorch (available in `torch.__config__.show()`).