do not bother with assert_nothing_raised, the test will fail and we get a better trace without it

activerecord/test/cases/associations/has_many_through_associations_test.rb

@@ -770,9 +770,7 @@ def test_primary_key_option_on_source
   def test_create_should_not_raise_exception_when_join_record_has_errors
     repair_validations(Categorization) do
       Categorization.validate { |r| r.errors[:base] << 'Invalid Categorization' }
-      assert_nothing_raised do
-        Category.create(:name => 'Fishing', :authors => [Author.first])
-      end
+      Category.create(:name => 'Fishing', :authors => [Author.first])
     end
   end
 end