$ kube-mail 
QObject: Cannot create children for a parent that is in a different thread.
(Parent is QGuiApplication(0x7ffd93e34300), parent's thread is QThread(0x1a61fe0), current thread is QThread(0x1bc0950)
QObject::installEventFilter(): Cannot filter events for objects in a different thread.
QQmlApplicationEngine failed to load component
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:19 module "QtQuick.Controls" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:20 module "QtQuick.Layouts" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:23 module "org.kde.kube.actions" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:19 module "QtQuick.Controls" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:20 module "QtQuick.Layouts" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:23 module "org.kde.kube.actions" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:19 module "QtQuick.Controls" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:20 module "QtQuick.Layouts" is not installed
file:///usr/local/share/kpackage/pim/org.kde.kube.mail/contents/ui/main.qml:23 module "org.kde.kube.actions" is not installed

QObject: Cannot create children for a parent that is in a different thread.
(Parent is QGuiApplication(0x7ffd93e34300), parent's thread is QThread(0x1a61fe0), current thread is QThread(0x1bc0950)
QObject::installEventFilter(): Cannot filter events for objects in a different thread.