diff -ur spack-src/Makefile new/Makefile
--- spack-src/Makefile	2015-04-28 02:21:27.000000000 +0900
+++ new/Makefile	2019-07-01 15:12:04.985193793 +0900
@@ -186,10 +186,10 @@
 else
 DEFINES = $(DEFINESLINUX) $(DEFINESCOMMON)
 ifndef CM64
-CM64 = -m64
+CM64 =
 endif
 ifndef FM64
-FM64 = -m64
+FM64 =
 endif
 endif