长话短说
sudo cp -p /etc/network/if-up.d/resolved /etc/network/if-up.d/.resolved.broken-orig
#Edit /etc/network/if-up.d/resolved and take out the extraneous quotes on lines 48 and 52
#The fix looks like:
diff /etc/network/if-up.d/.resolved.broken-orig /etc/network/if-up.d/resolved
48c48
< "$DNS"="$NEW_DNS"
---
> $DNS="$NEW_DNS"
52c52
< "$DOMAINS"="$NEW_DOMAINS"
---
> $DOMAINS="$NEW_DOMAINS"
至少，这看起来是有效的。
最近通过将旧系统升级到 Ubuntu 22.04.1 LTSdo-release-upgrade并遇到 DNS 问题，错误消息为：
nslookup google.com
Server: 127.0.0.53
Address: 127.0.0.53#53
** server can't find google.com: SERVFAIL
和
/etc/network/if-down.d/resolved: 12: mystatedir: not found
/etc/network/if-up.d/resolved: 71: DNS: not found
/etc/network/if-up.d/resolved: 1: /run/network/ifupdown-inet-em1: DNS=8.8.8.8: not found
/etc/network/if-up.d/resolved: 2: /run/network/ifupdown-inet-em1: DOMAINS=local_search_domain.com: …