KDE Neon Bionic UE. All repos standard (3-d party PPA's not added)
LOG:

Code: Select all

sudo apt install qt5-style-plugins
Чтение списков пакетов… Готово
Построение дерева зависимостей       
Чтение информации о состоянии… Готово
Starting pkgProblemResolver with broken count: 1
Starting 2 pkgProblemResolver with broken count: 1
Investigating (0) qt5-style-plugins:amd64 < none -> 5.0.0+git23.g335dbec-2build5 @un puN Ib >
Broken qt5-style-plugins:amd64 Зависит on qtbase-abi-5-9-5:amd64 < none @un H >
  Considering libqt5core5a:amd64 3164 as a solution to qt5-style-plugins:amd64 9999
Done
Некоторые пакеты невозможно установить. Возможно, вы просите невозможного,
или же используете нестабильную версию дистрибутива, где запрошенные вами
пакеты ещё не созданы или были удалены из Incoming.
Следующая информация, возможно, поможет вам:

Пакеты, имеющие неудовлетворённые зависимости:
 qt5-style-plugins : Зависит: qtbase-abi-5-9-5
E: Невозможно исправить ошибки, у вас отложены (held) битые пакеты.

Translate (by Google):

Code: Select all

sudo apt install qt5-style-plugins
Reading package lists ... Done
Building a dependency tree
Reading status information ... Done
Start pkgProblemResolver with a broken account: 1
Starting from 2 pkgProblemResolver with a broken account: 1
Investigation (0) qt5-style-plugins: amd64 <none -> 5.0.0 + git23.g335dbec-2build5 @un puN Ib>
Broken qt5-style plugins: amd64 Depends on qtbase-abi-5-9-5: amd64 <none @un H>
Considering libqt5core5a: amd64 3164 as a solution for qt5-style-plugins: amd64 9999
Is done
Some packages cannot be installed. Perhaps you are asking for the impossible,
or use the unstable version of the distributive where you are late
In addition.
The following information may help you:

Packages with unsatisfied dependencies:
qt5-style-plugins: Depends: qtbase-abi-5-9-5
E: It is impossible to correct the errors, you have postponed the broken packages.

I have this problem too i want to install the Motif theme and relive the old days of X (even though I'm not old enough to remember them)

These are not KDE and not supported in Neon. They come from the main Ubuntu archive, and depend on the version on Qt that they were built with there, which is not compatible with the version in Neon.

If you really want them, an option would be to grab the sources and rebuild on your system with Neon's Qt version.

@acheronuk Thank you! I'll go try to do that now. (Even though I should be doing homework, LOL )