no luck with Qt 5.9.2

[Jan Mulder]

>> Unfortunately, very very limited progress. I found out that 2nd code fragment above does not tell the whole story. Obviously, it needs an "import QtQuick.Controls 2.2" the get the ApplicationWindow defined. However, adding "import org.kde.kirigami 2.0 as Kirigami" triggers the exit on the "can't create window object". So, its only one input that triggers the error of an almost empty main.qml
>>
>> The big question is now: is it Kirigami or Qt/QML? Of even a combination of both?
> 
> Have you tried running this under strace to see if it tries to open some library that it can't find or something?
> I haven't been able to reproduce this on the desktop, only on iOS for some reason - and I have no idea how to run strace there :-(
> 
>> I even tried to compile mobile-on-desktop against the beta of Qt 5.10.0. No luck there, and the exact same behavior.


Ok, again having some time after the release of 4.7.1, I investigated 
this issue further.

First. I'm (still) very tempted to say that it is a Kirigami issue, 
that's why I put Marco in the to list.

With commenting 1 line of code in Kirigami, the Subsurface code: 
engine.load(QUrl(QStringLiteral("qrc:///qml/main.qml"))) passes. That 
one line of code is:

qmlRegisterSingletonType(componentUrl(QStringLiteral("Units.qml")), uri, 
2, 0, "Units")

from kirigamiplugin.cpp.

Obviously, our code fails somewhere later, as we use the units 
extensively. Looked trough the git history of Kirigami and do not see 
anything obvious, so I am still not 100% sure that it is Kirigami, as 
there is also some relation to Qt 5.9.2.

So, Marco, do you see any lead here what might be going on? I just do 
not understand enough with respect to qmlRegisterType stuff.

--jan