QSignalSpy crashed the test executable when testing a static lib.

[CKurdu]

While testing a static library, the test app crashed due to QSignalSpy.

Project structure.

test CMakeLists.txt

cmake_minimum_required(VERSION 3.16)
project(testsubject LANGUAGES CXX)

set(CMAKE_AUTOMOC ON)


find_package(Qt6 REQUIRED COMPONENTS Core Gui Test Widgets)

qt_add_executable(testsubject
    testsubject.cpp
)

set_target_properties(testsubject PROPERTIES
    WIN32_EXECUTABLE TRUE
    MACOSX_BUNDLE TRUE
)

target_link_libraries(testsubject PUBLIC
    Qt::Core
    Qt::Gui
    Qt::Test
    Qt::Widgets
    subject
)

testsubject.cpp

#include <QTest>
#include "subject.h"
#include <QSignalSpy>

class TestSubject: public QObject
{
    Q_OBJECT
    Subject* m_subject;
private slots:
    void name();
    void initTestCase()
    {
        m_subject = new Subject();
    }
};


void TestSubject::name()
{
    QSignalSpy spy(m_subject,&Subject::nameChanged);
    m_subject->setName("cafer");
    spy.wait();
    QCOMPARE(spy.count(),1);
}

QTEST_MAIN(TestSubject)
#include "testsubject.moc"

result

When I use subject source files without linking them statically adding directly, there are no problems.

The crash occurs when the spy object gets destroyed.

I'm unsure if this is a bug or I'm doing something incorrectly. Can you help me figure it out?

[Christian Ehrlicher]

As always - use a debugger to see where it crashes. And then simplify the application until it either no longer crashes or you found the bug. If it's small enough, post a minimal, compilable reproducer here.

[CKurdu]

Thank you for your quick response @Christian-Ehrlicher

This is already a minimal example and below is a GitHub repository show that.

https://github.com/ckurdu/staticlib_qttest

It's interesting that the same problem started happening when I added subject files directly, so I think I am making a mistake this is not a bug.

[CKurdu]

@Christian-Ehrlicher
The situation is turning strange because MinGW compiler works well with all styles, static or not.

[CKurdu]

The problem only occurs in debug mode.

When Qt Creator is in debug mode, the program crashes.

OMG, I spent four hours on this.

[CKurdu]

The problem occurs with below config

Qt 6 6 0 MSVC2019 64bit debug.
debug mode

[Christian Ehrlicher]

Then you somehow mix debug and release libraries which is not supported with MSVC.

[CKurdu]

@Christian-Ehrlicher
I think you are right. Because, on my other PC, there is no problem. I tried many things.
I removed the debug folder to try to start the config cmake project from scratch. It didn't work. Now I am reinstalling Qt 6.6.0

[CKurdu]

The problem was solved after I reinstalled Qt 6.6.0. However, I am still unsure of what caused the issue in the first place.

Thank You @Christian-Ehrlicher