--- ghc-8.4.3/mk/warnings.mk~	2018-02-04 02:30:11.000000000 +0900
+++ ghc-8.4.3/mk/warnings.mk	2018-09-29 14:33:37.607884921 +0900
@@ -1,6 +1,6 @@
 # See Note [Order of warning flags].
-SRC_CC_OPTS     += -Wall $(WERROR)
+#SRC_CC_OPTS     += -Wall $(WERROR)
 SRC_HC_OPTS     += -Wall
 # Don't add -Werror to SRC_HC_OPTS_STAGE0 (or SRC_HC_OPTS), because otherwise
 # validate may unnecessarily fail when booting with an older compiler.
 # It would be better to only exclude certain warnings from becoming errors

Diff finished.  Sat Sep 29 14:35:43 2018