我有 Ubuntu 20.04，我尝试使用docker login登录终端，但得到：
docker login
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: sfelshtyn
Password:
Error saving credentials: error storing credentials - err: exit status 1, out: `error getting credentials - err: exit status 1, out:` no usernames for https://index.docker.io/v1/``