All those who are trying to build KStars within version 3.6.4 and greater on Ubuntu 20,04 LTS watch out!
Ubuntu 20,04 uses KF5 Version 5.68.0 which does not support anymore some new parts of the KF5-code. The prominent error is the following (excerpt of buildlog from launchpad):
<code>/<<PKGBUILDDIR>>/kstars/ekos/ekoslive/cloud.cpp: In constructor ‘EkosLive::Cloud::Cloud(Ekos::Manager*)’:
/<<PKGBUILDDIR>>/kstars/ekos/ekoslive/cloud.cpp:35:40: error: ‘EkosLiveCloudChanged’ is not a member of ‘Options’
35 | connect(Options::self(), &Options::EkosLiveCloudChanged, this, &Cloud::updateOptions);
| ^~~~~~~~~~~~~~~~~~~~</code>

Toni,

Are you running Ubuntu or Kubuntu? I'm running Kubuntu and I started getting notices around the start of the year that certain parts of Kubuntu 20.04 LTS were no longer going to be supported. (Yeah -- it's confusing -- still not quite sure what is supported and what's not.) I upgraded to 22.04 LTS about a month ago with no issues.

Bob

You need KF5 v78 or above, so that's only available 22.04 or later.

So it's final: KStars >= 3.6.4 will not run on Ubuntu 20.04 LTS anymore!?

I could compile it just fine if I commented that line out. Maybe add #if KCONFIG_VERSION >= QT_VERSION_CHECK(5,78,0)
Yes ekos live will not work but better than not be able to compile at all?

So it hasn't worked for quite a while now. We switched to a new Options/Settings system that relies on properties. That was done a while ago, and while you could still *compile* KStars , many places in KStars were using the property system and so most likely this means many of your settings were not retained properly. So yes, 20.04 is dropped from support.

OK! I switched to Ubuntu 22.04 LTS and all is well now!