error: 'friend' used outside of class

/Users/qt/work/qt/qtopcua_build/include/QtDeclarativeOpcua/6.5.0/QtDeclarativeOpcua/private/../../../../../../qtopcua/src/declarative_opcua/opcuastatus_p.h:292:5: error: 'friend' used outside of class
QML_UNCREATABLE("This type can not be created.")
^
/Users/qt/work/install/include/QtQmlIntegration/qqmlintegration.h:57:34: note: expanded from macro 'QML_UNCREATABLE'
template<typename, typename> friend struct QML_PRIVATE_NAMESPACE::QmlUncreatable; \
^
In file included from /Users/qt/work/qt/qtopcua_build/src/declarative_opcua/DeclarativeOpcua_autogen/mocs_compilation.cpp:5:
In file included from /Users/qt/work/qt/qtopcua_build/src/declarative_opcua/DeclarativeOpcua_autogen/EWIEGA46WW/moc_opcuaconnection_p.cpp:9:
In file included from /Users/qt/work/qt/qtopcua_build/src/declarative_opcua/DeclarativeOpcua_autogen/EWIEGA46WW/../../../../../qtopcua/src/declarative_opcua/opcuaconnection_p.h:7:
In file included from /Users/qt/work/qt/qtopcua_build/include/QtDeclarativeOpcua/6.5.0/QtDeclarativeOpcua/private/opcuaserverdiscovery_p.h:1:
In file included from /Users/qt/work/qt/qtopcua_build/include/QtDeclarativeOpcua/6.5.0/QtDeclarativeOpcua/private/../../../../../../qtopcua/src/declarative_opcua/opcuaserverdiscovery_p.h:7:
In file included from /Users/qt/work/qt/qtopcua_build/include/QtDeclarativeOpcua/6.5.0/QtDeclarativeOpcua/private/opcuastatus_p.h:1:
/Users/qt/work/qt/qtopcua_build/include/QtDeclarativeOpcua/6.5.0/QtDeclarativeOpcua/private/../../../../../../qtopcua/src/declarative_opcua/opcuastatus_p.h:292:5: error: cannot define or redeclare 'QmlUncreatable' here because namespace 'OpcuaStatusForeign' does not enclose namespace 'QQmlPrivate'