Failed to set DNS configuration: Link lo is loopback device after Upgrade to Ubuntu 24.04

[nemihome]

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preferably after they have been already discussed and confirmed to be reproducible.

FOR ASSISTANCE, PLEASE CLOSE THIS FORM AND USE THE DISCUSSIONS SECTION INSTEAD:
https://github.com/DNSCrypt/dnscrypt-proxy/discussions/categories/q-a

Reported bugs must reproducible in the context described in the "Context" section.

Installation and configuration issues are not bugs, but individual assistance request.

Context: the LATEST version of `dnscrypt-proxy` (precompiled binaries downloaded from this repository) is correctly installed and configured on your system, but something doesn't seem to produce the expected result.

If the bug is not trivial to reproduce on any platform, please include ALL the steps required to reliably duplicate it, on a vanilla, generic install of macOS, Windows, OpenBSD or Ubuntu Linux system, in their most current version.

If you don't have any clear understanding of the issue or can't enumerate the steps to reproduce it, open a discussion instead:
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## Output of the following commands:

./dnscrypt-proxy -version 
2.0.45

./dnscrypt-proxy -check

dnscrypt-proxy -check
[2024-07-20 16:33:43] [NOTICE] dnscrypt-proxy 2.0.45
[2024-07-20 16:33:43] [NOTICE] Source [relays] loaded
[2024-07-20 16:33:43] [NOTICE] Source [public-resolvers] loaded
[2024-07-20 16:33:43] [NOTICE] Anonymized DNS: routing [quad9-dnscrypt-ip4-nofilter-ecs-pri] via [anon-ams-nl anon-pwoss.org anon-pf]
[2024-07-20 16:33:43] [NOTICE] Configuration successfully checked

./dnscrypt-proxy -resolve example.com

Resolving [example.com] using 127.0.0.1 port 10053

- [ ] Initially raised as discussion #...



## *What* is affected by this bug?

Service dnscrypt-proxy-resolvconf.service does not start due to Failed to set DNS configuration: Link lo is loopback device.

## *When* does this occur?

Service startup

## *Where* does it happen?



## *How* do we replicate the issue?
<!-- Please list all the steps required to reliably replicate it, starting from a newly installed operating system -->

Update from Ubuntu 22.04 to Ubuntu 24.04 with dnscrypt-proxy installed

## Expected behavior (i.e. solution)

No error at startup

## Other Comments

This seems to be very similar to https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/2067897. As far as I understand this is a bug which is caused because of new Ubuntu behavior + assumtions of strongswan developers.

I installed Ubuntu 24.04 on a second drive so I could compare before and after. With 22.04 the service looks like this:
"sudo service dnscrypt-proxy-resolvconf status
○ dnscrypt-proxy-resolvconf.service - DNSCrypt proxy resolvconf support
     Loaded: loaded (/lib/systemd/system/dnscrypt-proxy-resolvconf.service; enabled; vendor preset: enabled)
     Active: inactive (dead)
  Condition: start condition failed at Sat 2024-07-20 16:49:56 CEST; 1min 40s ago
             └─ ConditionFileIsExecutable=/sbin/resolvconf was not met
       Docs: https://github.com/DNSCrypt/dnscrypt-proxy/wiki

Jul 20 16:49:56 od.backprod.de systemd[1]: Condition check resulted in DNSCrypt proxy resolvconf support being skipped."

That means with 22.04 it is not started whereas with 24.04 it is started because start condition is not met and not working.

[jedisct1]

dnscrypt-proxy-resolvconf doesn't exist indnscrypt-proxy.

That seems to be an addition from Ubuntu. Try uninstalling and reinstalling the Ubuntu package, maybe. If it doesn't work, Ubuntu-related forums may be a better place to ask for help.