Disable 'set but unused' warning on MacOS

Author: sodero

build/Makefile

@@ -34,7 +34,7 @@ CDEF = -D_DEFAULT_SOURCE -D_GNU_SOURCE
 else
 ifeq ($(OS),Darwin)
 CGEN = -g -std=c99
-CWRN += -Wno-invalid-utf8
+CWRN += -Wno-invalid-utf8 -Wno-unused-but-set-variable
 else
 ifeq ($(OS),Windows_NT)
 CC = x86_64-w64-mingw32-gcc.exe