GLib.Variants Invalid GVariant format string for `d(du)`

[zspher]

To give context, i am trying to automate clightd with Gio.DBusProxy in python. Relevant parts of the script are as follows:

from gi.repository import GLib, Gio
clight_backlight = Gio.DBusProxy.new_for_bus_sync(
    Gio.BusType.SYSTEM,
    Gio.DBusProxyFlags.NONE,
    None,
    'org.clightd.clightd',
    '/org/clightd/clightd/Backlight2',
    'org.clightd.clightd.Backlight2',
    None)

def decrease_brightness(n: int, clight_backlight: Gio.DBusProxy):
    clight_backlight.call_sync('Raise', 
                               (GLib.Variant('d(du)', 
                                             (0.05, 
                                              GLib.Variant('(du)', (0.0, 0)))
                                             )), 
                               Gio.DBusCallFlags.NO_AUTO_START, 500, None)

decrease_brightness(5, clight_backlight)

when using GLib.Variant('d(du)', (0.5, GLib.Variant('(du)', (0.0, 0)))) - d(du), TypeError: ("Invalid GVariant format string '%s'", 'd(du)') is thrown

however when using GLib.Variant('(d(du))', (0.5, GLib.Variant('(du)', (0.0, 0)))) - (d(du)) everything in a tuple, no error is thrown

the clightd API accepts d(du) (e.g./org/clightd/clightd/Backlight2 Set) so i can't automate it with GDbus. Anyway, just going to use busctl.

[FedeDP]

Hi! I am not very familiar with the python dbus API unfortunately...

when using GLib.Variant('d(du)', (0.5, GLib.Variant('(du)', (0.0, 0)))) - d(du), TypeError: ("Invalid GVariant format string '%s'", > 'd(du)') is thrown however when using GLib.Variant('(d(du))', (0.5, GLib.Variant('(du)', (0.0, 0)))) - (d(du)) everything in a tuple, no error is thrown

Perhaps this is a bug in the library? I mean, busctl accepts it and the sd-bus library allows it!

[zspher]

yup this might be a problem with the python library