compiled QMLs incompatible between minor version changes - c++

Question

I have a very simple QML app made with Qt 5.12 that runs fine on an linux embedded device. It consists of only one qml resource.
The device has recently gotten an OS update and now Qt 5.14 is available.
However the app now cannot run because of this error:
QQmlApplicationEngine failed to load component
qrc:/main.qml:-1 File was compiled ahead of time with an incompatible version of Qt and the original file cannot be found. Please recompile
It is a shame that with such a small version change i would need to keep both binaries for compatibility. I read some stuff on the internet saying to add CONFIG += qtquickcompiler to enable compilation before start, but it didn't change anything. The binary size is the same.
I haven't experienced such problems when not using QML, could even launch Qt5.9 compiled apps on Qt5.12 without problem.
That's basically all of my main.cpp:
int main(int argc, char *argv[])
{
QTextCodec::setCodecForLocale(QTextCodec::codecForName("UTF-8"));
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
QGuiApplication app(argc, argv);
QQmlApplicationEngine engine;
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
if (engine.rootObjects().isEmpty())
return -1;
return app.exec();
}
The QML file itself only imports
import QtQuick 2.5
import QtQuick.Window 2.2
Is there anything I can do to preserve compatibility without storing a binary for each version I'm going to support? I could probably store the raw qml file right next to the binary and load it from the disk, but I'd rather keep it stored in the app resources.
I have confirmed it works fine when using QUrl::fromLocalFile, but I really don't like to have all the qml files lying around. Is there any way to store the qml as a resource AND not compile it? I know it's worse for start performance but I'm willing to accept it for compatibility

Answer 1

I think I found the way myself, actually the qtquickcompiler is enabled by default and removing it from the config resulted in a smaller binary size and launched properly on the newer Qt environment without having any local QML files (still using qrc) and also after clearing the QML cache.
CONFIG -= qtquickcompiler
In case no one has any better way to preserve compatibility, I'll mark this as accepted