minor fix

.github/workflows/build.yml

@@ -112,24 +112,16 @@ jobs:
         run: |
           apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64/3bf863cc.pub
           apt-key adv --fetch-keys https://developer.download.nvidia.com/compute/machine-learning/repos/ubuntu1804/x86_64/7fa2af80.pub
-      - name: Install CUDA
-        run: |
-          export INSTALLER=cuda-repo-${UBUNTU_VERSION}_${CUDA}_amd64.deb
-          wget http://developer.download.nvidia.com/compute/cuda/repos/${UBUNTU_VERSION}/x86_64/${INSTALLER}
-          sudo dpkg -i ${INSTALLER}
-          wget https://developer.download.nvidia.com/compute/cuda/repos/${UBUNTU_VERSION}/x86_64/7fa2af80.pub
-          sudo apt-key add 7fa2af80.pub
-          sudo apt update -qq
-          sudo apt install -y cuda-${CUDA_SHORT/./-} cuda-cufft-dev-${CUDA_SHORT/./-}
-          sudo apt clean
-          export CUDA_HOME=/usr/local/cuda-${CUDA_SHORT}
-          export LD_LIBRARY_PATH=${CUDA_HOME}/lib64:${CUDA_HOME}/include:${LD_LIBRARY_PATH}
-          export PATH=${CUDA_HOME}/bin:${PATH}
+      - name: Install system dependencies
+        run: apt-get update && apt-get install -y libgl1-mesa-glx libglib2.0-0 libsm6 libxrender-dev libxext6
+      - name: Install python-dev
+        run: apt-get update && apt-get install -y python${{matrix.python-version}}-dev
+        if: ${{matrix.python-version != '3.9'}}
       - name: Install Pillow
         run: pip install Pillow==6.2.2
         if: ${{matrix.torchvision < 0.5}}
       - name: Install PyTorch
-        run: pip install torch==${{matrix.torch}} torchvision==${{matrix.torchvision}} -f https://download.pytorch.org/whl/torch_stable.html
+        run: python -m pip install torch==${{matrix.torch}} torchvision==${{matrix.torchvision}} -f https://download.pytorch.org/whl/torch_stable.html
       - name: Install MMCV
         run: |
           pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu101/torch${{matrix.mmcv}}/index.html