gistfile1.txt

commit 0cf884df64c307d4c9322e1ad7eb28f9e8efec31 (HEAD -> backport-ruby-core)
Author: Hiroshi SHIBATA <hsbt@ruby-lang.org>
Date:   2019-11-12 15:44:19 +0900

    Only enabled mon_owned condition with Ruby 2.5+

diff --git lib/rubygems/core_ext/kernel_require.rb lib/rubygems/core_ext/kernel_require.rb
index d2bcc508e5..0be5172040 100644
--- lib/rubygems/core_ext/kernel_require.rb
+++ lib/rubygems/core_ext/kernel_require.rb
@@ -32,7 +32,9 @@ module Kernel
   # that file has already been loaded is preserved.

   def require(path)
-    monitor_owned = RUBYGEMS_ACTIVATION_MONITOR.mon_owned?
+    if RUBY_PLATFORM >= '2.5'
+      monitor_owned = RUBYGEMS_ACTIVATION_MONITOR.mon_owned?
+    end
     RUBYGEMS_ACTIVATION_MONITOR.enter

     path = path.to_path if path.respond_to? :to_path
@@ -167,9 +169,11 @@ module Kernel

     raise load_error
   ensure
-    if monitor_owned != (ow = RUBYGEMS_ACTIVATION_MONITOR.mon_owned?)
-      STDERR.puts [$$, Thread.current, $!, $!.backtrace].inspect if $!
-      raise "CRITICAL: RUBYGEMS_ACTIVATION_MONITOR.owned?: before #{monitor_owned} -> after #{ow}"
+    if RUBY_VERSION >= "2.5"
+      if monitor_owned != (ow = RUBYGEMS_ACTIVATION_MONITOR.mon_owned?)
+        STDERR.puts [$$, Thread.current, $!, $!.backtrace].inspect if $!
+        raise "CRITICAL: RUBYGEMS_ACTIVATION_MONITOR.owned?: before #{monitor_owned} -> after #{ow}"
+      end
     end
   end