--- xen-4.11.0/stubdom/Makefile.orig	2018-07-09 14:47:19.000000000 +0100
+++ xen-4.11.0/stubdom/Makefile	2018-07-11 22:33:00.764078143 +0100
@@ -87,7 +87,7 @@
 	patch -d $@ -p0 < newlib.patch
 	patch -d $@ -p0 < newlib-chk.patch
 	patch -d $@ -p1 < newlib-stdint-size_max-fix-from-1.17.0.patch
-	find $@ -type f | xargs perl -i.bak \
+	find $@ -type f | xargs egrep -l "tzname|daylight|timezone" | xargs perl -i.bak \
 		-pe 's/\b_(tzname|daylight|timezone)\b/$$1/g'
 	touch $@