More specific logging than xev

[Simon Hafner <reactormonk gmail com>]

Hey

I'm implementing some EWMH with emacs. There is a function
(x-send-client-message) to send X messages. According to xev -root,
the root window receives

ClientMessage event, serial 20, synthetic YES, window 0x2200012,
    message_type 0x13f (_NET_CURRENT_DESKTOP), format 32

but does not switch desktop. `wmctrl -s 1` gives the same message

ClientMessage event, serial 26, synthetic YES, window 0xab,
    message_type 0x13f (_NET_CURRENT_DESKTOP), format 32

but it switches desktops. How can I debug that further?

Greetings
Simon Hafner