Couldn't download https://raw.githubusercontent.com/certbot/certbot/v1.2.0/letsencrypt-auto-source/letsencrypt-auto

Couldn't download https://raw.githubusercontent.com/certbot/certbot/v1.2.0/letsencrypt-auto-source/letsencrypt-auto

Upgrading certbot-auto 1.0.0 to 1.2.0...

Couldn't download https://raw.githubusercontent.com/certbot/certbot/v1.2.0/letsencrypt-auto-source/letsencrypt-auto. <urlopen error [Errno 111] Connection refused>

原因是：certbot-auto将始终尝试从最新版本中获取自身的最新版本。

解决方案也非常简单：

如果希望将其锁定到特定版本并且不接收自动更新，只需在命令后加 --no-self-upgrade 即可。即：

1	certbot-auto renew --no-self-upgrade

果然，问题解决！