Comment 4 for bug 1974072

First it is good to be clear about a couple of details relative to how Debian/Ubuntu packaging works with various library versions. The packaging system is designed to generally allow co-installation of multiple versions of the same library without any issue whatsoever. However, these Linphone packages have unusual version constraints with an upper limit as well, which is not the norm for almost any libraries. This means that in this instance libortp13 cannot be co-installed with libortp15 due the earlier libortp13 still having the libbctoolbox1 << 0.7.0 restriction.

So the continuing issue here is to do with the kopete package specifically, which I did not realise is a dependency of the KDE meta-packages you mentioned in the original bug report, and that is why the issue is not fully resolved yet. Due kopete depending on libortp13 and due this unusual situation with very restrictive versioning for the libbctoolbox1 dependency it will indeed require rebuilding kopete against newer libortp15 for the issue to be fully resolved. This will be done, the rebuilt kopete will be uploaded to ppa:savoury1/multimedia, and then this bug will be updated once the kopete rebuild is published.

Also, if you happen to want newer Qt/KDE packages than Focal default you can look at ppa:savoury1/qt-5-15 [1] and ppa:savoury1/kde-5-80 [2] which have backports of Qt 5.15.2 and compatible KDE packages. Interestingly, the newer kde-standard package backported to the mentioned KDE PPA no longer depends on kopete due kopete not being in Debian, so kopete was not part of the backported suite of KDE packages so far. However, it will now be also added to ppa:savoury1/kde-5-80 for users such as yourself who use that software.

[1] https://launchpad.net/~savoury1/+archive/ubuntu/qt-5-15
[2] https://launchpad.net/~savoury1/+archive/ubuntu/kde-5-80