From 6a1644ddca64e81839bc5f9953dea692dcac7b70 Mon Sep 17 00:00:00 2001
From: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date: Mon, 27 Oct 2025 15:05:33 +0900
Subject: [ruby/rubygems] If we use shared GEM_HOME and install multiple
 versions, it may cause unexpected test failures.

```
       Fetching gem metadata from https://gem.repo4/.
       Resolving dependencies...
       Resolving dependencies...
       # $? => 0
       cannot load such file -- diff/lcs
```

https://github.com/ruby/rubygems/commit/668b300261
---
 spec/bundler/spec_helper.rb | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/spec/bundler/spec_helper.rb b/spec/bundler/spec_helper.rb
index 87bdf8b9f3..d750218452 100644
--- a/spec/bundler/spec_helper.rb
+++ b/spec/bundler/spec_helper.rb
@@ -19,6 +19,10 @@ ENV["VISUAL"] = nil
 ENV["BUNDLER_EDITOR"] = nil
 require "bundler"
 
+# If we use shared GEM_HOME and install multiple versions, it may cause
+# unexpected test failures.
+gem "diff-lcs"
+
 require "rspec/core"
 require "rspec/expectations"
 require "rspec/mocks"
-- 
cgit v1.2.3