问题

我出现了以下问题

Get:1 https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu1804/x86_64  InRelease [1581 B]
Err:1 https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu1804/x86_64  InRelease
  Couldn't create temporary file /tmp/apt.conf.L9miaT for passing config to apt-key
Reading package lists... Done
W: GPG error: https://developer.download.nvidia.cn/compute/cuda/repos/ubuntu1804/x86_64  InRelease: Couldn't create temporary file /tmp/apt.conf.L9miaT for passing config to apt-key
E: The repository 'https://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64  InRelease' is not 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.

解决办法
在使用apt-get update之前修改/tmp文件夹权限。

chmod 777 /tmp