--- ruby-2.2.3/tool/rbinstall.rb.orig	2015-10-21 16:08:38.834317272 +0300
+++ ruby-2.2.3/tool/rbinstall.rb	2015-10-21 16:10:44.364295637 +0300
@@ -665,7 +665,7 @@
 install?(:ext, :comm, :gem) do
   $:.unshift(File.join(srcdir, "lib"))
   require("rubygems.rb")
-  gem_dir = Gem.default_dir
+  gem_dir = Gem.respond_to?(:default_dirs) ? Gem.default_dirs[:local][:gem_dir] : "/usr/share/gems"
   directories = Gem.ensure_gem_subdirectories(gem_dir, :mode => $dir_mode)
   prepare "default gems", gem_dir, directories
 
@@ -724,11 +724,11 @@
   end
   if defined?(Zlib)
     require 'pathname'
-    gem_dir = Gem.default_dir
+    gem_dir = Gem.respond_to?(:default_dirs) ? Gem.default_dirs[:local][:gem_dir] : "/usr/share/gems"
     directories = Gem.ensure_gem_subdirectories(gem_dir, :mode => $dir_mode)
     prepare "bundle gems", gem_dir, directories
     Dir.glob(srcdir+'/gems/*.gem').each do |gem|
-      Gem.install gem, Gem::Requirement.default, :install_dir => with_destdir(Gem.dir), :domain => :local, :ignore_dependencies => true
+      Gem.install gem, Gem::Requirement.default, :install_dir => with_destdir(gem_dir), :domain => :local, :ignore_dependencies => true
       gemname = Pathname(gem).basename
       puts "#{" "*30}#{gemname}"
     end