XML for Systemd DBus?

[Elsie Hupp <xdg@xxxxxxxxxxxxx>]

Note: I am on elementaryOS 6.0.

I am trying to generate a vala interface from the Systemd DBus interface, following the example here to get the XML to feed into `vala-dbus-binding-tool`:

https://wiki.gnome.org/Projects/Vala/DBusClientSamples

But I am getting the following error:

```bash
$ dbus-send --print-reply --type=method_call --dest=org.freedesktop.systemd1 objectpath org.freedesktop.DBus.Introspectable.Introspect
dbus[208973]: arguments to dbus_message_new_method_call() were incorrect, assertion "_dbus_check_is_valid_path (path)" failed in file ../../../dbus/dbus-message.c line 1366.
This is normally a bug in some application using the D-Bus library.

  D-Bus not built with -rdynamic so unable to print a backtrace
Aborted (core dumped)
```

I tried with a specific interface, as well:

```bash
$ dbus-send --print-reply --type=method_call --dest=org.freedesktop.systemd1.Device objectpath org.freedesktop.DBus.Introspectable.Introspect
dbus[164720]: arguments to dbus_message_new_method_call() were incorrect, assertion "_dbus_check_is_valid_path (path)" failed in file ../../../dbus/dbus-message.c line 1366.
This is normally a bug in some application using the D-Bus library.

  D-Bus not built with -rdynamic so unable to print a backtrace
Aborted
```

I did several web searches of the error messages, and none of them were particularly helpful.

How do I get the XML for the Systemd DBus interface? Is there a way I can work around this error, or is there a copy available somewhere online?