Just rescue exception rather than checking for both miniunit and test/unit

activesupport/test/abstract_unit.rb

@@ -5,6 +5,7 @@
 $:.unshift "#{File.dirname(__FILE__)}/../lib"
 $:.unshift File.dirname(__FILE__)
 require 'active_support'
+require 'active_support/test_case'
 
 if RUBY_VERSION < '1.9'
   $KCODE = 'UTF8'

activesupport/test/test_test.rb

 require 'abstract_unit'
-require 'active_support/test_case'
 
 class AssertDifferenceTest < ActiveSupport::TestCase
   def setup
@@ -66,10 +65,8 @@ def test_array_of_expressions_identify_failure
         @object.increment
       end
       fail 'should not get to here'
-    rescue MiniTest::Assertion => e
+    rescue Exception => e
       assert_equal "<3> expected but was\n<2>.", e.message
-    rescue Test::Unit::AssertionFailedError => e
-      assert_equal "<1 + 1> was the expression that failed.\n<3> expected but was\n<2>.", e.message
     end
 
     def test_array_of_expressions_identify_failure_when_message_provided
@@ -77,10 +74,8 @@ def test_array_of_expressions_identify_failure_when_message_provided
         @object.increment
       end
       fail 'should not get to here'
-    rescue MiniTest::Assertion => e
+    rescue Exception => e
       assert_equal "something went wrong.\n<3> expected but was\n<2>.", e.message
-    rescue Test::Unit::AssertionFailedError => e
-      assert_equal "something went wrong.\n<1 + 1> was the expression that failed.\n<3> expected but was\n<2>.", e.message
     end
   else
     def default_test; end