Fix Clang build error.
@@ -19,6 +19,7 @@ CFLAGS += -Wall
CFLAGS += -Wextra
CFLAGS += -Wpedantic
CFLAGS += -Werror
+CFLAGS += -Wno-unused-command-line-argument
ifeq ($(SANITIZE), yes)
CFLAGS += -fsanitize=address
CFLAGS += -fsanitize=undefined
