New comment by bakuhatu on void-packages repository

https://github.com/void-linux/void-packages/issues/31274#issuecomment-1019578144

Comment:
I might have done the `QT_LOGGING_RULES` thing wrong last time.

I tried again with `QT_LOGGING_RULES="*.debug=true" /usr/lib64/libexec/xdg-desktop-portal-kde -v`

saw this: 
`kf.crash: Could not find drkonqi in search paths: ("/usr/lib/libexec", "/usr/lib/qt5/libexec", "/usr/lib64/libexec")` 

but no  `kf.wayland.client: Unknown interface announced: zkde_screencast_unstable_v1`

Also, I tried looking at [waylandintegration.cpp](https://invent.kde.org/plasma/xdg-desktop-portal-kde/-/blob/master/src/waylandintegration.cpp):

```
connect(m_registry, &KWayland::Client::Registry::interfaceAnnounced, this, [this](const QByteArray &interfaceName, quint32 name, quint32 version) {
        if (interfaceName != "zkde_screencast_unstable_v1")
            return;
        m_screencasting = new Screencasting(m_registry, name, version, this);
    });
```
This is the part @Johnnynator was talking about I guess. 
I think it's connecting an interfaceAnnounced signal to m_registry, but I don't understand what the last two parameters are for and I can't find what `connect` is. My C++ knowledge is pretty basic so idk.

I couldn't find the `interfaceAnnounced` implementation, though I found the declaration in [kwayland/registry.h](https://github.com/KDE/kwayland/blob/10e3d60ab413e4389b9ecf88909f854f6eddbf1c/src/client/registry.h). I guess the implementation is the 4th argument to connect, but I don't know how to find where it calls that function/emits that signal to see what it's using as `interfaceName`.