Hi! I'm working on a piece of software that extensively uses QDBus. The project is based on Qt5. I'm trying to upgrade it to Qt6 but have encountered an issue with QDBus that's described in detail in my official bug report[1]. The report includes a link to a github repo with reproducible examples.
Short version is: it's impossible to connect to the InterfacesAdded or InterfacesRemoved signals (and potentially to any signals that have slightly more complex arguments) on the system bus with QDBus in Qt6 (unless one enables QDBUS_DEBUG=1 in which case it's possible). I suspect some timing issue/race condition but don't know Qt enough to debug it. While my project is not related to KDE, I thought I'd bring it to your attention (as KDE is scheduled to upgrade to Qt6). This bug definitely affects KDE as for instance the networkmanager-qt project subscribes for the InterfacesAdded signal of NetworkManager's paths and will no longer work with Qt6. Has anyone in the KDE community encountered this bug yet? How does KDE deal with blockers like this? Seems like Qt is not eager to fix it on their side. Best regards, Bartosz Golaszewski [1] https://bugreports.qt.io/projects/QTBUG/issues/QTBUG-108822