Created attachment 267041 [details] log showing failure libxkbcommon fails to compile due to some overquoting. From the log: -DDFLT_XKB_CONFIG_ROOT='""/usr/share/X11/xkb""' Must be a problem with the xorg-2 eclass?
Looks like an upstream problem, actually. Patch sent to fix it: http://lists.x.org/archives/xorg-devel/2011-March/020671.html
*** This bug has been marked as a duplicate of bug 358637 ***