Crash in QQmlBinding::create

0   QtQml                           0x109cc908c         QQmlBinding::create (qqmlbinding.cpp:128)
1   QtQuick                         0x108b6e5d6         QQmlAnyBinding::createFromCodeString (qqmlanybinding_p.h:202)
2   QtQuick                         0x108b878fc         QQuickPropertyChanges::changeExpression (qquickpropertychanges.cpp:704)
3   QtQuick                         0x108c04ac7         QQuickDesignerSupportPropertyChanges::changeExpression (qquickdesignersupportpropertychanges.cpp:109)
4   qml2puppet                      0x106c88ee9         <unknown>
5   qml2puppet                      0x106c89c95         <unknown>
6   qml2puppet                      0x106ccd64e         <unknown>
7   qml2puppet                      0x106c49ade         <unknown>
8   qml2puppet                      0x106c45c3b         <unknown>
9   QtCore                          0x1095eeedd         doActivate<T> (qobject.cpp:3921)
10  QtCore                          0x1095ef171         doActivate<T> (qobject.cpp:3933)
11  QtNetwork                       0x10929467a         QAbstractSocketPrivate::canReadNotification (qabstractsocket.cpp:696)
12  QtNetwork                       0x10929c9dd         QReadNotifier::event (qnativesocketengine.cpp:1272)
13  QtWidgets                       0x1075ab2f6         QApplicationPrivate::notify_helper (qapplication.cpp:3350)
14  QtWidgets                       0x1075ac2b2         QApplication::notify (qapplication.cpp:2754)
15  QtCore                          0x10959f189         QCoreApplication::notifyInternal2 (qcoreapplication.cpp:1067)
16  QtCore                          0x10970cd1e         qt_mac_socket_callback (qcfsocketnotifier.cpp:75)
17  CoreFoundation                  0x7ff81d98def9      __CFSocketPerformV0
18  CoreFoundation                  0x7ff81d9648fc      __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
19  CoreFoundation                  0x7ff81d964864      __CFRunLoopDoSource0
20  CoreFoundation                  0x7ff81d9645e3      __CFRunLoopDoSources0
21  CoreFoundation                  0x7ff81d96301a      __CFRunLoopRun
22  CoreFoundation                  0x7ff81d9625dc      CFRunLoopRunSpecific
23  HIToolbox                       0x7ff82659f4f0      RunCurrentEventLoopInMode
24  HIToolbox                       0x7ff82659f246      ReceiveNextEventCommon
25  HIToolbox                       0x7ff82659efe4      _BlockUntilNextEventMatchingListInModeWithFilter
26  AppKit                          0x7ff820391d87      _DPSNextEvent
27  AppKit                          0x7ff8203903f3      -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
28  AppKit                          0x7ff820382918      -[NSApplication run]
29  libqcocoa.dylib                 0x107db3fbb         QCocoaEventDispatcher::processEvents (qcocoaeventdispatcher.mm:430)
30  QtCore                          0x1095a8875         QEventLoop::exec (qeventloop.cpp:218)
31  QtCore                          0x10959f784         QCoreApplication::exec (qcoreapplication.cpp:1388)
32  qml2puppet                      0x106c4496f         <unknown>
33  qml2puppet                      0x106c425e3         <unknown>
34  dyld                            0x107ecf4fd         start

QQmlBinding *QQmlBinding::create(
        const QQmlPropertyData *property, const QString &str, QObject *obj,
        const QQmlRefPointer<QQmlContextData> &ctxt, const QString &url, quint16 lineNumber)
{
    QQmlBinding *b = newBinding(QQmlEnginePrivate::get(ctxt), property);
    b->setNotifyOnValueChanged(true);
    b->QQmlJavaScriptExpression::setContext(ctxt);
    b->setScopeObject(obj);