From fd6d582427f75eee2373bdcbaa598365c6eb76a9 Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Tue, 1 Jul 2025 17:38:25 +0900
Subject: [PATCH] [ruby/etc] Run `have_func` with the header providing the
 declarations

https://github.com/ruby/etc/commit/6668bfd42a
---
 ext/etc/extconf.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/etc/extconf.rb b/ext/etc/extconf.rb
index 2e28d58037..c4929c02d2 100644
--- a/ext/etc/extconf.rb
+++ b/ext/etc/extconf.rb
@@ -58,7 +58,7 @@ end
 # TODO: remove when dropping 2.7 support, as exported since 3.0
 have_func('rb_deprecate_constant(Qnil, "None")')
 
-have_func("rb_io_descriptor")
+have_func("rb_io_descriptor", "ruby/io.h")
 
 $distcleanfiles << "constdefs.h"