commit 4c2356a37baa44e692e2c26120d92c60ef213d0d
Author: Pavel Skrylev <majioa@altlinux.org>
Date:   Mon Aug 15 21:36:43 2022 +0300

    fix: support of multiple gem tree

diff --git a/lib/rubygems/defaults.rb b/lib/rubygems/defaults.rb
index 228748fe57..a2a4bfa77e 100644
--- a/lib/rubygems/defaults.rb
+++ b/lib/rubygems/defaults.rb
@@ -183,6 +183,9 @@ def self.default_path
     path = []
     path << user_dir if user_home && File.exist?(user_home)
     path << default_dir
+    path |= %w(rubylibdir rubyarchdir).map do |key|
+      Dir.glob(File.join(RbConfig::CONFIG[key], 'gems', '{,[0-9]?[0-9]?[0-9]}'))
+    end.flatten.select {|x| File.directory?(x) }
     path << vendor_dir if vendor_dir and File.directory? vendor_dir
     path
   end