This fixes tests on 1.9.3

lib/bundler.rb

@@ -1,6 +1,12 @@
 require 'rbconfig'
 require 'fileutils'
 require 'pathname'
+
+begin
+  require 'psych'
+rescue LoadError
+end
+
 require 'yaml'
 require 'bundler/rubygems_ext'
 require 'bundler/version'

lib/bundler/cli.rb

@@ -1,6 +1,7 @@
 $:.unshift File.expand_path('../vendor', __FILE__)
 require 'thor'
 require 'thor/actions'
+require 'rubygems/user_interaction'
 require 'rubygems/config_file'
 
 # Work around a RubyGems bug

lib/bundler/rubygems_ext.rb

@@ -105,6 +105,12 @@ class Dependency
 
     alias eql? ==
 
+    def encode_with(coder)
+      to_yaml_properties.each do |ivar|
+        coder[ivar.to_s.sub(/^@/, '')] = instance_variable_get(ivar)
+      end
+    end
+
     def to_yaml_properties
       instance_variables.reject { |p| ["@source", "@groups"].include?(p.to_s) }
     end

lib/bundler/source.rb

@@ -1,4 +1,5 @@
 require "uri"
+require 'rubygems/user_interaction'
 require "rubygems/installer"
 require "rubygems/spec_fetcher"
 require "rubygems/format"

lib/bundler/ui.rb

@@ -1,3 +1,5 @@
+require 'rubygems/user_interaction'
+
 module Bundler
   class UI
     def warn(message)

spec/support/rubygems_ext.rb

@@ -1,3 +1,5 @@
+require 'rubygems/user_interaction'
+
 module Spec
   module Rubygems
     def self.setup