xopt => getopt_long. I give up on xopt. It didn't help me as much as I had hoped, and I had problems building for mingw with only some versions of GCC. Not worth any further time.

GNUmakefile

@@ -245,7 +245,6 @@ $(APP_OBJS): CFLAGS += \
 	-Ideps/quickjs \
 	-Ideps/sqlite \
 	-Ideps/valgrind \
-	-Ideps/xopt \
 	-Wdouble-promotion \
 	-Werror
 ifeq ($(UNAME_M),x86_64)
@@ -497,18 +496,6 @@ $(SQLITE_OBJS): CFLAGS += \
 	-Wno-unused-function \
 	-Wno-unused-variable
 
-XOPT_SOURCES := deps/xopt/xopt.c
-XOPT_OBJS := $(call get_objs,XOPT_SOURCES)
-$(filter $(BUILD_DIR)/win%,$(XOPT_OBJS)): CFLAGS += \
-	-DHAVE_SNPRINTF \
-	-DHAVE_VSNPRINTF \
-	-DHAVE_VASNPRINTF \
-	-DHAVE_VASPRINTF \
-	-Dvsnprintf=rpl_vsnprintf
-$(XOPT_OBJS): CFLAGS += \
-	-Wno-implicit-const-int-float-conversion \
-	-Wno-pointer-to-int-cast
-
 QUICKJS_SOURCES := \
 	deps/quickjs/cutils.c \
 	deps/quickjs/libbf.c \
@@ -637,8 +624,7 @@ ALL_APP_OBJS := \
 	$(QUICKJS_OBJS) \
 	$(SODIUM_OBJS) \
 	$(SQLITE_OBJS) \
-	$(UV_OBJS) \
-	$(XOPT_OBJS)
+	$(UV_OBJS)
 
 DEPS = $(ALL_APP_OBJS:.o=.d)
 -include $(DEPS)