Hi Dave!
A snowy winter day, so been doing some investigation of QT 6.8.1 to try to understand some of the problems it has. One thing I did is compare the names of DLL's in QT 6.2.11 with the ones in 6.8.1 and found some discrepancies.
What is this snow thing you speak of? Is it that thing we see here on Christmas cards?
In the \lib directory, there are 3 files missing from 6.8 that are found in 6.2: Qt6NetAu.dll, Qt6PosQk.dll, and QtQmlCoe.dll. Probably their names were changed somehow in the latest build - there is a posquick.dll and Qt6QmCoe.dll in 6.8 I believe are the equivalent for QtPosQk.dll and QtQmlCoe.dll. Can't find an equivalent for Qt6NetAu.dll in 6.8.
1st one is simple - I haven't built qtnetworkauth for 6.8.1
2nd one is interesting... I had uncommited changes to define OS2_SHORT_NAME in 6.2.x then in 6.8.x chose different names <sigh> will fill now.
3rd one is even more interesting.... OS2_SHORT_NAME is defined in 6.2.x (
https://github.com/psmedley/qt6-declarative-os2/blob/main/src/core/CMakeLists.txt#L18) but for reasons I don't recall right now (or it was a typo) I changed it in 6.8.x (
https://github.com/psmedley/qt6-declarative-os2/blob/6.8.x/src/core/CMakeLists.txt#L23) - actually looks I messed it up in 6.5.x
In the \qml directory there are several name changes in 6.8.1 from 6.2.11:
\QtCore\QtQmlCoe.dll in 6.2 is Qt6QmCoe.dll in 6.8
\QtPositioning\Qt6PosQk.dll in 6.2 is posquick.dll in 6.8
\QtQml\qmlplugn.dll in 6.2 is qml.dll in 6.8
\QtQml\Base\ directory does not exist in 6.2 or 6.8, but does exist in 6.6
\QtWebchannel\Webchann.dll in 6.2 is Qt6WebCQ.dll in 6.8
A couple of these are explained above, qmlplugn.dll vs qml.dll reminds me of some stuff experimenting with qtdeclarative a ways back - I suspect some 'drift' between 6.2 and 6.5 - and 6.8 is based on 6.5
This could definitely explain why some apps that use qml and were build against older Qt don't work. Leave it with me to investigate....
On top of that, there are some qmldir files missing the 'plugin' or 'optional plugin' directive in the \qml directory in 6.8, and the strange addition of another 'QML' directory there which just doesn't look right to me. Most of the qmldir files with missing directives are in new directories not found in 6.2. They are:
I have no real clues about this....
Really appreciate this analysis, I think it should hopefully help speed up some fixes....