Qt 6.0.0 Alpha App fails to compile with MSVC and /std:c++latest

C:\Qt\6.0.0\msvc2019_64\include\QtCore/qmetatype.h(2310): error C2370: 'QtPrivate::QMetaTypeForType<S>::name': redefinition; different storage class
C:\Qt\6.0.0\msvc2019_64\include\QtCore/qmetatype.h(2220): note: see declaration of 'QtPrivate::QMetaTypeForType<S>::name'
C:\Qt\6.0.0\msvc2019_64\include\QtCore/qmetatype.h(2310): error C2059: syntax error: '='
C:\Qt\6.0.0\msvc2019_64\include\QtCore/qmetatype.h(2310): error C2065: 'T': undeclared identifier

#include <QApplication>
#include <QMainWindow>
class MainWindow : public QMainWindow
{
    Q_OBJECT
public:
    MainWindow (QWidget *parent = 0) : QMainWindow(parent) {};
    ~MainWindow(                   ) {};
};

int main(int argc, char *argv[]){
    QApplication app(argc, argv);
    MainWindow main_window;
    main_window.show();
    return app.exec();
}

cl.exe /nologo /TP -DQT_CORE_LIB -DQT_GUI_LIB -DQT_WIDGETS_LIB -DQT_WINMAIN_LIB -DUNICODE -DWIN32 -DWIN64 -D_ENABLE_EXTENDED_ALIGNED_STORAGE -D_UNICODE -D_WIN64 -IC:\Qt\6.0.0\msvc2019_64\include\QtCore -IC:\Qt\6.0.0\msvc2019_64\mkspecs\win32-msvc -IC:\Qt\6.0.0\msvc2019_64\include -IC:\Qt\6.0.0\msvc2019_64\include\QtGui -IC:\VulkanSDK\1.2.135.0\Include -IC:\Qt\6.0.0\msvc2019_64\include\QtWidgets /DWIN32 /D_WINDOWS /W3 /GR /EHsc /MDd /Zi /Ob0 /Od /RTC1 -Zc:__cplusplus -utf-8 -std:c++latest /FoCMakeFiles\msmanager.dir\main.cpp.obj /FS -c main.cpp