xen-tools dependency on x11-proto/xproto can be removed by patching the ebuild when not using ioemu USE flag. (patch attached) Reproducible: Always Steps to Reproduce:
Created attachment 118191 [details, diff] xen-tools-noX11.patch This is the pached (compiles fine without any x11-* stuffs installed)
Thanks for the patch, fixed in CVS now.