Crash due to Qt version difference

[PhysSong]

I've found this bug when I tried to use a VST in LMMS after upgrading Qt. If a client uses different Qt version from the version used when building this, the client crashes with the error:

Cannot mix incompatible Qt library (version 0x50904) with this library (version 0x50905)

This is where it crashes:

QObjectPrivate::QObjectPrivate(int version)
    : threadData(0), connectionLists(0), senders(0), currentSender(0), currentChildBeingDeleted(0)
{
#ifdef QT_BUILD_INTERNAL
    // Don't check the version parameter in internal builds.
    // This allows incompatible versions to be loaded, possibly for testing.
    Q_UNUSED(version);
#else
    if (Q_UNLIKELY(version != QObjectPrivateVersion))
        qFatal("Cannot mix incompatible Qt library (version 0x%x) with this library (version 0x%x)",
                version, QObjectPrivateVersion);
#endif

Are there any ways to work around this on clients' side or fix this on this library's side?

[lukas-w]

I don't think there's a clean way to work around this. We need access to QWidgetPrivate's methods to implement this. We could explicitly pass a different version to QObjectPrivate's constructor, but that's really nasty. So the library will have to be rebuilt for every Qt version specifically.