--- iasl-20171215.ebuild.orig	2018-10-02 10:16:11.807604000 +0800
+++ iasl-20171215.ebuild	2018-10-02 10:16:47.246672800 +0800
@@ -44,7 +44,7 @@
 
 	find "${S}" -type f -name 'Makefile*' -print0 | \
 		xargs -0 -I '{}' \
-		sed -r -e 's:-\<Werror\>::g' -i '{}' \
+		sed -r -e 's:-\<Werror\>::g' -e "s:/usr:${EPREFIX}/usr:g" -i '{}' \
 		|| die
 
 	# BITS is tied to ARCH - please set appropriately if you add new keywords