Crash in debug but not in release

[Franckynos]

I have made some function in my code like this method:

 MyMessageBox m(this);
    m.setText(tr("Chargement des goupilles..."));
    QPixmap p(":/icones/wait");
    p=p.scaled(150,150);
    QMovie *mov = new QMovie(":/gif/wait");
    m.setStartMovie(mov);
    m.showButtons(false,false);
    m.setObjectName("Mon message d'attente");

    //BUG: PROBLEME ICI plantage en mode debug
    QtConcurrent::run(this, SelectGoupRef::runFindPins, &m);
    m.exec();

    this->accept();

The current class is QDialog(this)
I create a messageBox to show a waiting state for the user, the runFindPins is the process and when the computation is done, is say "accept" to MyMessageBox (m.accept();).

In Release mode all work fine but in Debug my app crash ???

[jsulm]

You should NEVER manipulate UI from a different thread!
This is not supported. Instead you should emit a signal from the thread which is connected to a slot in main thread which closes the message box (use Qt::QueuedConnection in connect(...)).

[Franckynos]

You have right I change with:=>

QFutureWatcher<void> watcher;
    connect(&watcher, SIGNAL(finished()), &m, SLOT(accept()));
    watcher.setFuture(QtConcurrent::run(this, &SelectGoupRef::runFindPins, &watcher));

And no problem in debug.

Thx