1. 密钥错误
Err:1 http://sunrise.horizon.cc/ubuntu-journey focal InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 599F576057BDF67C
Err:2 http://sunrise.horizon.cc/ubuntu-rdkultra focal InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 599F576057BDF67C使用以下命令更新密钥：
sudo wget -O /usr/share/keyrings/sunrise.gpg http://sunrise.horizon.cc/keys/sunrise.gpg
sudo apt update2. 最近源的主域名换成了archive.d-robotics.cc，所以sudo apt update时会报如下错误：
sunrise@ubuntu:~$ sudo apt update
Hit:1 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal InRelease
Hit:2 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-security InRelease
Hit:3 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-updates InRelease
Hit:4 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-backports InRelease
Hit:5 http://packages.ros.org/ros2/ubuntu focal InRelease
Get:6 http://archive.sunrisepi.tech/ubuntu-rdk focal InRelease
Err:6 http://archive.sunrisepi.tech/ubuntu-rdk focal InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Reading package lists... Done
E: Failed to fetch http://archive.sunrisepi.tech/ubuntu-rdk/dists/focal/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://archive.sunrisepi.tech/ubuntu-rdk focal 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.RDK Ultra会报如下错误：
root@ubuntu:~# apt update
Hit:1 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal InRelease
Hit:2 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-security InRelease
Err:3 http://archive.sunrisepi.tech/ubuntu-journey focal InRelease
Could not resolve 'archive.sunrisepi.tech'
Err:4 http://archive.sunrisepi.tech/ubuntu-rdkultra focal InRelease
Could not resolve 'archive.sunrisepi.tech'
Hit:5 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-updates InRelease
Hit:6 http://mirrors.tuna.tsinghua.edu.cn/ubuntu-ports focal-backports InRelease
Hit:7 http://packages.ros.org/ros2/ubuntu focal InRelease
Reading package lists... Done
Building dependency tree
Reading state information... Done
180 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: Failed to fetch http://archive.sunrisepi.tech/ubuntu-journey/dists/focal/InRelease Could not resolve 'archive.sunrisepi.tech'
W: Failed to fetch http://archive.sunrisepi.tech/ubuntu-rdkultra/dists/focal/InRelease Could not resolve 'archive.sunrisepi.tech'
W: Some index files failed to download. They have been ignored, or old ones used instead.可以采用以下命令将源替换，解决这个问题：
sudo sed -i 's/archive\.sunrisepi\.tech/archive\.d-robotics\.cc/g' /etc/apt/sources.list.d/sunrise.list或者：
sudo sed -i 's/sunrise\.horizon\.cc/archive\.d-robotics\.cc/g' /etc/apt/sources.list.d/sunrise.list
