From 80e9105afbc0efc4054a50170e9f86642e475eae Mon Sep 17 00:00:00 2001
From: dearblue <dearblue@gmx.com>
Date: Sat, 25 Oct 2025 21:05:39 +0900
Subject: [PATCH] Explicitly include `errno.h`

This is required for `ENOSYS`.
---
 mrbgems/hal-win-socket/src/socket_hal.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mrbgems/hal-win-socket/src/socket_hal.c b/mrbgems/hal-win-socket/src/socket_hal.c
index 9b28d324a..3acda0b5e 100644
--- a/mrbgems/hal-win-socket/src/socket_hal.c
+++ b/mrbgems/hal-win-socket/src/socket_hal.c
@@ -20,6 +20,7 @@
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #include <windows.h>
+#include <errno.h>
 #include <string.h>
 
 /*