Created attachment 5101 0001-Add-with-vala-api-option-to-allow-packagers-select-v.patch Let packagers set what vala API version they want build the bindings, rather than require the they use whatever the xfce4-vala maintainer's distro happens to use.
commited, thank you :) http://git.xfce.org/bindings/xfce4-vala/commit/?id=6d0ef92197b94c1b1722b02e5f730e6af80ded6f best regards, mike