Running alalcarte (GNOME's menu editor) in a console will give you:

==========================
** (process:515): WARNING **: Trying to register gtype 'GMountMountFlags' as enum when in fact it is of type 'GFlags'

** (process:515): WARNING **: Trying to register gtype 'GDriveStartFlags' as enum when in fact it is of type 'GFlags'

** (process:515): WARNING **: Trying to register gtype 'GSocketMsgFlags' as enum when in fact it is of type 'GFlags'
Traceback (most recent call last):
  File "/usr/bin/alacarte", line 22, in <module>
    from Alacarte.MainWindow import MainWindow
  File "/usr/lib/python2.7/site-packages/Alacarte/MainWindow.py", line 19, in <module>
    import gtk, gmenu, gobject, gio
ImportError: No module named gmenu
==============================

It seems python-gmenu or whatever is called the package providing gmenu.so is not available in the repositories. urpmf gmenu.so returns an empty result.