From 2df72c0c1a686052ab00f853bb15bd67dcbfedd4 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@oriontransfer.co.nz>
Date: Wed, 24 Dec 2025 13:09:05 +1300
Subject: [PATCH] Fix flaky test.

---
 test/fiber/scheduler.rb      | 2 +-
 test/fiber/test_scheduler.rb | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/test/fiber/scheduler.rb b/test/fiber/scheduler.rb
index 07b15c5ce4..820c46dfb0 100644
--- a/test/fiber/scheduler.rb
+++ b/test/fiber/scheduler.rb
@@ -497,7 +497,7 @@ class IOScheduler < Scheduler
     fd = io.fileno
     str = buffer.get_string
     __io_ops__ << [:io_write, fd, str]
-    Fiber.blocking { buffer.write(IO.for_fd(fd), 0, offset) }
+    Fiber.blocking { buffer.write(io, 0, offset) }
   end
 end
 
diff --git a/test/fiber/test_scheduler.rb b/test/fiber/test_scheduler.rb
index c20fe86ff4..0cbd49daca 100644
--- a/test/fiber/test_scheduler.rb
+++ b/test/fiber/test_scheduler.rb
@@ -287,7 +287,6 @@ class TestFiberScheduler < Test::Unit::TestCase
   end
 
   def test_io_write_on_flush
-    omit "skip this test because it makes CI fragile"
     begin
       fn = File.join(Dir.tmpdir, "ruby_test_io_write_on_flush_#{SecureRandom.hex}")
       write_fd = nil