@raven-worx Thanks!

I ran into the same problem and this problem is very very annoying during daily work.

I filed a bug report for that issue.

Release builds using the QtQuick compiler generate a qtquickcompiler_loader.cpp file and *_qml.cpp files where * matches the name of your individual *.qml files all within a ".qtquickcompiler" folder within the "build-*-Release" output folder. I verified this with a commercial license Qt 5.9.

Debugging QML is not compatible with the QtQuick compiler; using default settings to build a Debug executable will not use the QtQuick compiler.