From 430b28d05dc49defdb45552be8f8a7e109fd13ea Mon Sep 17 00:00:00 2001
From: "Peter H. Boling" <peter.boling@gmail.com>
Date: Mon, 5 Jan 2026 14:48:26 -0700
Subject: [PATCH] =?UTF-8?q?=E2=9C=A8=20feat:=20add=20Ruby=204.1=20version?=
 =?UTF-8?q?=20support=20for=20ruby-head=20compatibility?=
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Ruby 4.1 (ruby-head) introduces breaking C API changes that require
conditional compilation in dependent crates. This adds 4.1 to the
supported version arrays to enable ruby_lt_4_1, ruby_gte_4_1, and
related cfg flags.

Changes:
- Add Version::new(4, 1) to SUPPORTED_RUBY_VERSIONS in rb-sys
- Add (4, 0) and (4, 1) to COMPARABLE_RUBY_MINORS in rb-sys-env

This enables crates like magnus to handle the rb_data_type_struct
change where 'reserved' was replaced with 'handle_weak_references'.

Closes #696
---
 crates/rb-sys-env/src/ruby_version.rs | 4 +++-
 crates/rb-sys/build/main.rs           | 3 ++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/crates/rb-sys-env/src/ruby_version.rs b/crates/rb-sys-env/src/ruby_version.rs
index 9d30dccad..43a330ea4 100644
--- a/crates/rb-sys-env/src/ruby_version.rs
+++ b/crates/rb-sys-env/src/ruby_version.rs
@@ -2,7 +2,7 @@ use std::collections::HashMap;
 
 const COMPARABLE_RUBY_MAJORS: [u8; 4] = [1, 2, 3, 4];
 
-const COMPARABLE_RUBY_MINORS: [(u8, u8); 11] = [
+const COMPARABLE_RUBY_MINORS: [(u8, u8); 13] = [
     (2, 2),
     (2, 3),
     (2, 4),
@@ -14,6 +14,8 @@ const COMPARABLE_RUBY_MINORS: [(u8, u8); 11] = [
     (3, 2),
     (3, 3),
     (3, 4),
+    (4, 0),
+    (4, 1),
 ];
 
 /// The current Ruby version.
diff --git a/crates/rb-sys/build/main.rs b/crates/rb-sys/build/main.rs
index e95e6885e..9eb4f77d6 100644
--- a/crates/rb-sys/build/main.rs
+++ b/crates/rb-sys/build/main.rs
@@ -13,7 +13,7 @@ use std::{
 };
 use version::Version;
 
-const SUPPORTED_RUBY_VERSIONS: [Version; 11] = [
+const SUPPORTED_RUBY_VERSIONS: [Version; 12] = [
     Version::new(2, 3),
     Version::new(2, 4),
     Version::new(2, 5),
@@ -25,6 +25,7 @@ const SUPPORTED_RUBY_VERSIONS: [Version; 11] = [
     Version::new(3, 3),
     Version::new(3, 4),
     Version::new(4, 0),
+    Version::new(4, 1),
 ];
 
 fn main() {