diff --git a/test/rubygems/test_gem_gem_runner.rb b/test/rubygems/test_gem_gem_runner.rb
index b5d8581bea..0a1faa404a 100644
--- a/test/rubygems/test_gem_gem_runner.rb
+++ b/test/rubygems/test_gem_gem_runner.rb
@@ -1,17 +1,36 @@
 # frozen_string_literal: true
 require 'rubygems/test_case'
 begin
-  require 'rubygems/gem_runner'
-ensure
-  if $!
+  gem_home_files = lambda{
     if Dir.exist?(ENV["GEM_HOME"])
       require "find"
       ary = Find.find(ENV["GEM_HOME"]).to_a
-      raise <<eom
-GEM_HOME: #{ENV["GEM_HOME"]}
-contant: #{ary.inspect}
-eom
+    else
+      []
     end
+  }
+  prev_gem_home = ENV["GEM_HOME"]
+  prev_gem_home_files = gem_home_files.call
+  prev_threads = Thread.list.map{|e| e.inspect}
+
+  require 'rubygems/gem_runner'
+ensure
+  if $!
+    msg = <<eom
+***************
+PREV
+  GEM_HOME: #{prev_gem_home}
+  Files in GEM_HOME: #{prev_gem_home_files.inspect}
+  Threads: #{prev_threads.inspect}
+Current:
+  GEM_HOME: #{ENV["GEM_HOME"]}
+  Files in GEM_HOME: #{gem_home_files.call}
+  Threads: #{Thread.list.map{|e| e.inspect}.inspect}
+Exception: #{$!.message}
+eom
+    p $!.class
+    p $!.message.frozen?
+    raise $!.class, msg, $!.backtrace
   end
 end