W: GPG error: https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu2004/x86_64 InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A4B469963BF863CC E: The repository 'https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64 InRelease' is no longer signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.
来源：https://askubuntu.com/questions/1408016/the-following-signatures-couldnt-be-verified-because-the-public-key-is-not-avai
wget https://developer.download.nvidia.com/compute/cuda/repos/ubuntu2004/x86_64/cuda-keyring_1.0-1_all.deb
dpkg -i cuda-keyring_1.0-1_all.deb
可能提示需要执行 apt-key del 7fa2af80