There was a new pyxdg release, 6 days ago according to the git repository, but "october" according to the website. In particular, this bug was fixed, making it work with KDE menus: https://bugs.freedesktop.org/show_bug.cgi?id=56426 Just renaming the ebuild works, although this might be a good opportunity to modernize it. (Btw, it's kind of annoying that the examples get installed bzipped and thus not runnable)
Added to CVS.