Created attachment 5881 Patch, which adds support of libxfce4ui >= 4.11 If xfce4-screenshooter is build with libxfce4ui >= 4.11, 'xfce_dialog_show_help' function is empty, patch replaces this one by 'xfce_dialog_show_help_with_version'.
I thought we had fixed that but apparently not. Please apply this patch and make a release before 4.12
I dont think we need this patch in xfce4-screenshooter, because libxfce4ui itself got fixed in http://git.xfce.org/xfce/libxfce4ui/commit/?id=686267e52e340f9160f050abb6949b2b7a469c7c, it's just that there's not been a libxfce4ui release since then.