In Neon User Edition 5.20, the Ubuntu package yubioath-desktop from universe is no longer installable due to broken dependencies. $ apt-cache policy yubioath-desktop yubioath-desktop: Installed: (none) Candidate: 5.0.3-1 Version table: 5.0.3-1 500 500 http://ca.archive.ubuntu.com/ubuntu focal/universe amd64 Packages $ sudo apt-get install yubioath-desktop Reading package lists... Done Building dependency tree Reading state information... Done Starting pkgProblemResolver with broken count: 1 Starting 2 pkgProblemResolver with broken count: 1 Investigating (0) yubioath-desktop:amd64 < none -> 5.0.3-1 @un puN Ib > Broken yubioath-desktop:amd64 Depends on qml-module-io-thp-pyotherside:amd64 < none | 1.5.9-1build1 @un uH > Considering qml-module-io-thp-pyotherside:amd64 1 as a solution to yubioath-desktop:amd64 9999 Reinst Failed early because of qtdeclarative-abi-5-12-8:amd64 Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help resolve the situation: The following packages have unmet dependencies: yubioath-desktop : Depends: qml-module-io-thp-pyotherside but it is not going to be installed E: Unable to correct problems, you have held broken packages
One limitation of neon is that we only care about KDE apps and anything outside KDE may end up like this incompatible and not able to be installed. There's better packaging technologies these days like using snaps or flatpaks or appimages maybe this app uses that.