Could not resolve ‘‘

Question:

orangepi@HiGuys:~$ sudo apt update
Err:1 /debian bullseye InRelease
  Could not resolve ''
Err:2 /debian bullseye-updates InRelease
  Could not resolve ''
Err:3 /debian bullseye-backports InRelease
  Could not resolve ''
Err:4 /debian-security bullseye-security InRelease
  Could not resolve ''
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
All packages are up to date.
W: Failed to fetch /debian/dists/bullseye/InRelease  Could not resolve ''
W: Failed to fetch /debian/dists/bullseye-updates/InRelease  Could not resolve ''
W: Failed to fetch /debian/dists/bullseye-backports/InRelease  Could not resolve ''
W: Failed to fetch /debian-security/dists/bullseye-security/InRelease  Could not resolve ''
W: Some index files failed to download. They have been ignored, or old ones used instead.

Solve:

真尴尬，我的是 DNS 配置文件写错了 XD，nameserver没写全

balabala@balabala:~$ sudo vim /etc/
##  文件主要的配置内容
# 我用的是路由器作为DNS，当然，你可以用其他的，或者自己搭设的
nameserver 192.168.3.1
#  结束

Solve:

这个是在找答案的路上，遇到的其他情况和解决方案
针对于 http与https 协议的，使用https加密协议的，可以使用加密的http协议的地址试一试
这个貌似主要针对于 清华的源(tsinghua)。因为主流的源中，只有清华的源中，http和https两种协议镜像地址是相同的。(gentoo 的 source mirrors 是只有tsinghua的是双协议同地址的)

# 临时将更新方式改为http方式, update一下
balabala@bala:~$ sudo apt update
# 然后，再次修改回HTTPS方式，update一下
balabala@bala:~$ sudo apt update && sudo upgrde -y
# 然后，应该就好了