Singleton QML components are mistaken as properties

22:09:45: Starting C:\Qt\Tools\QtDesignStudio\qt6_design_studio_reduced_version\bin\qml2puppet-4.2.0.exe --qml-runtime -I C:/work/MCU_Training_Material/CoffeMaker/imports -I C:/work/MCU_Training_Material/CoffeMaker/imports/CoffeeControls C:/work/MCU_Training_Material/CoffeMaker/BrewingProgress.qml "-qmljsdebugger=file:C:/Users/81808/AppData/Local/Temp/QtDesignStudio-IGHDXg/qtc-socket.VJUoqd,block,services:QmlPreview,DebugTranslation"...
QML debugging is enabled. Only use this in a safe environment.
Info: Starting QML Runtime ((null):0, (null))
Warning: CoreApp is not initialized! Falling back to QGuiApplication! ((null):0, (null))
Debug: QML Debugger: Connecting to socket C:/Users/81808/AppData/Local/Temp/QtDesignStudio-IGHDXg/qtc-socket.VJUoqd... ((null):0, (null))
Warning: QQmlApplicationEngine failed to load component ((null):0, (null))
Warning: file:///C:/work/MCU_Training_Material/CoffeMaker/BrewingProgress.qml:64:5: Non-existent attached object (file:///C:/work/MCU_Training_Material/CoffeMaker/BrewingProgress.qml:64, (null))
Critical: QEventDispatcherWin32::wakeUp: Failed to post a message (ウィンドウ ハンドルが無効です。) ((null):0, (null))
qml: Did not load any objects, exiting.
22:09:47: C:\Qt\Tools\QtDesignStudio\qt6_design_studio_reduced_version\bin\qml2puppet-4.2.0.exe exited with code 2
  

pragma Singleton
import QtQuick

Timer {
    id: root    
    signal brewFinished()
    signal brewProgressStep()
    function startBrew(strength: number, capacity: number, temperature: number) {
        m_brewTimer.setInterval(calculateProgressInterval(strength, capacity, temperature))
        m_brewTimer.start()
    }    
    property int m_tickcount
    readonly property int _BREW_PROGRESS_TICKCOUNT: 150
    readonly property int _DEFAULT_BREW_PROGRESS_INTERVAL: 20
    readonly property int _DEFAULT_PARAM_SUM: 4
    readonly property int _PARAM_MULTIPLIER: 3
    function calculateProgressInterval(strength: number, capacity: number, temperature: number) {
        let sumOfParams = strength + capacity + temperature;
        if (sumOfParams == _DEFAULT_PARAM_SUM) {
            return _DEFAULT_BREW_PROGRESS_INTERVAL;
        } else if (sumOfParams < _DEFAULT_PARAM_SUM && sumOfParams > 0) {
            return _DEFAULT_BREW_PROGRESS_INTERVAL - ((_DEFAULT_PARAM_SUM - sumOfParams) * _PARAM_MULTIPLIER);
        } else if (sumOfParams > _DEFAULT_PARAM_SUM) {
            return _DEFAULT_BREW_PROGRESS_INTERVAL + ((sumOfParams - _DEFAULT_PARAM_SUM) * _PARAM_MULTIPLIER);
        } else {
            return _DEFAULT_BREW_PROGRESS_INTERVAL - (_DEFAULT_PARAM_SUM * _PARAM_MULTIPLIER);
        }
    }    

    onTriggered: {
        if (m_tickCount < _BREW_PROGRESS_TICKCOUNT) {
            brewProgressStep();
            m_tickCount++;
        } else {
            stop();
            brewingFinished();
            m_tickCount = 0;
        }
    }
}
 

module Backend
singleton BrewTimer 1.0 BrewTimer.qml
CoffeeModel 1.0 CoffeeModel.qml
singleton TimeStamp 1.0 TimeStamp.qml
 

import QtQuick
import Constants
Item {
    width: Constants.width    // <-- Constants is Singleton
    height: Constants.height  // <-- Constants is Singleton
}