it’s a version match problem i meet it too. now solved as follows
driver: NVIDIA-Linux-x86_64-440.118.02.run
cuda: cuda_10.2.89_440.33.01_linux.run
cuda patch: cuda_10.2.2_linux.run
libcudnn:
libcudnn7_7.6.5.32-1+cuda10.2_amd64.deb
libcudnn7-dev_7.6.5.32-1+cuda10.2_amd64.deb
libcudnn7-doc_7.6.5.32-1+cuda10.2_amd64.deb
pytorch:
pip3 install torch==1.7.1 torchvision==0.8.2 torchaudio==0.7.2
#do not install torch 1.8.0