Qt new CMake API + qmllint + qt_add_qml_module - how to setup

Matthew11

So I switched my project to Qt 6.8 qt_add_qml_module() API, and wanted to try out the qmllint and qmlformat. I have dummy basic project:

C:.
    CMakeLists.txt
    main.cpp
    Main.qml
    MyButton.qml

The CMakeLists.txt:

cmake_minimum_required(VERSION 3.20)

project(qml-sample VERSION 0.1 LANGUAGES CXX)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
find_package(Qt6 6.8 REQUIRED COMPONENTS Quick)

qt_standard_project_setup(REQUIRES 6.8)

qt_add_executable(qml-sample main.cpp)
qt_add_qml_module(qml-sample
    URI AppMain
    VERSION 1.0
    QML_FILES
        Main.qml
        MyButton.qml
)

target_link_libraries(qml-sample PRIVATE Qt6::Quick)

The main.cpp:

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    QObject::connect(
        &engine,
        &QQmlApplicationEngine::objectCreationFailed,
        &app,
        []() { QCoreApplication::exit(-1); },
        Qt::QueuedConnection);
    engine.loadFromModule("AppMain", "Main");

    return app.exec();
}

The Main.qml:

import QtQuick 2.15
import QtQuick.Controls 2.15

Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")

    MyButton {
        anchors.centerIn: parent
        width: 100
        height: 50
    }
}

Add dummy control MyButton.qml:

import QtQuick 2.15
import QtQuick.Controls 2.15
import QtQuick.Layouts 2.15

Rectangle {
    Button {
        text: "Click me!"
        anchors.fill: parent
    }
}

And that works fine, when I call qmllint target qml-sample_qmllint by hand:

Info: C:/sandbox/qml-test/Main.qml:2:1: Unused import [unused-imports]
import QtQuick.Controls 2.15
^^^^^^
Info: C:/sandbox/qml-test/MyButton.qml:3:1: Unused import [unused-imports]
import QtQuick.Layouts 2.15
^^^^^^

and in QtCreator I can see that issues are reported too:

Now I wanted to modularize things, and made two separate QML modules - one with Main.qml the AppMain and one with my controls Controls, and link them to main application, so now structure looks like:

C:.
│   CMakeLists.txt
│   main.cpp
│   Main.qml
│
└───controls
        CMakeLists.txt
        MyButton.qml

So controls/CMakeLists.txt:

qt_add_qml_module(controls STATIC NO_PLUGIN
    URI Controls
    VERSION 1.0
    QML_FILES
        MyButton.qml
    OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/Controls
)

And main CMakeLists.txt changes:

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,13 +6,15 @@ find_package(Qt6 6.8 REQUIRED COMPONENTS Quick)
 
 qt_standard_project_setup(REQUIRES 6.8)
 
+add_subdirectory(controls)
+
 qt_add_executable(qml-sample main.cpp)
-qt_add_qml_module(qml-sample
+qt_add_qml_module(app-main STATIC NO_PLUGIN
     URI AppMain
     VERSION 1.0
     QML_FILES
         Main.qml
-        MyButton.qml
+    OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/AppMain
 )
 
-target_link_libraries(qml-sample PRIVATE Qt6::Quick)
+target_link_libraries(qml-sample PRIVATE Qt6::Quick app-main controls)

And project still compiles and works fine, but qmllint is not working - i get many errors when calling qmllint targets for app-main:

Warning: C:/sandbox/qml-test/Main.qml:10:5: MyButton was not found. Did you add all imports and dependencies? [import]
    MyButton {
    ^^^^^^^^
Info: Did you mean "Button"?
    Button {
    ^^^^^^
Warning: C:/sandbox/qml-test/Main.qml:11:9: unknown grouped property scope anchors. [unqualified]
        anchors.centerIn: parent
        ^^^^^^^
Warning: C:/sandbox/qml-test/Main.qml:10:5: 'MyButton' is used but it is not resolved [unresolved-type]
    MyButton {
    ^^^^^^^^
Warning: C:/sandbox/qml-test/Main.qml:11:9: 'anchors' is used but it is not resolved [unresolved-type]
        anchors.centerIn: parent
        ^^^^^^^
...

QtCreator is also confused:

What I'm missing or not doing? Any help appreciated :)