Only in xen-tools//files: xen-tools-3.4.2-ldflags.patch
diff -ur xen-tools.orig//xen-tools-3.4.2-r4.ebuild xen-tools//xen-tools-3.4.2-r4.ebuild
--- xen-tools.orig//xen-tools-3.4.2-r4.ebuild	2011-09-28 04:49:50.310729247 +0800
+++ xen-tools//xen-tools-3.4.2-r4.ebuild	2011-09-28 06:57:40.990726129 +0800
@@ -70,6 +70,11 @@
 QA_EXECSTACK="usr/share/xen/qemu/openbios-sparc32
 	usr/share/xen/qemu/openbios-sparc64"
 
+if [ -x /.config/ ]; then
+	ewarn "system has a dir /.config, this need be removed to all the package to emerge"
+	exit 1;
+fi
+
 pkg_setup() {
 	export "CONFIG_LOMOUNT=y"