From 94432675ed3bc75af66c412ddf5fc658084448ec Mon Sep 17 00:00:00 2001
From: Peter Goldstein <peter.m.goldstein@gmail.com>
Date: Tue, 18 Jan 2022 00:53:13 -0800
Subject: [PATCH] Add Ruby 3.1 and ruby-head to CI and fix undef that fails on
 ruby-head

---
 .github/workflows/actions.yml | 2 +-
 lib/fakefs/pathname.rb        | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/fakefs/pathname.rb b/lib/fakefs/pathname.rb
index 5398494..120aa74 100644
--- a/lib/fakefs/pathname.rb
+++ b/lib/fakefs/pathname.rb
@@ -1035,6 +1035,6 @@ def empty?
 
   # Pathname class
   class Pathname
-    undef =~
+    undef =~ if respond_to?(:=~)
   end
 end