Ruby on rails 如何消除这些小测试错误/警告？

我有一个rails 3.2.14项目，我正在Windows7机器上开发

我最近在运行

bundle exec rspec

时开始收到这些警告：

MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/test/unit/testcase.rb:8:in '<module:Unit>' 
MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.14/lib/active_support/test_case.rb:12:in '<module:ActiveSupport>'
MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.14/lib/active_support/descendants_tracker.rb:34:in 'inherited'
MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.14/lib/active_support/descendants_tracker.rb:34:in 'inherited'
MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.14/lib/active_support/descendants_tracker.rb:34:in 'inherited'
MiniTest::Unit::TestCase is now Minitest::Test. From C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/activesupport-3.2.14/lib/active_support/descendants_tracker.rb:34:in 'inherited'
Run options: include {:focus=>true}

但是，一旦我这样做了，当测试完成时，我会出现以下错误：

C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `write': closed stream (IOError)
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `puts'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `puts'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:1069:in `_run'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:1059:in `run'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:795:in `block in autorun'

考虑到ruby可能有问题，我升级到1.9.3.p429，但没有乐趣，这种行为仍然存在。我怎样才能修好这些

C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `write': closed stream (IOError)
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `puts'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:849:in `puts'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:1069:in `_run'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:1059:in `run'
from C:/RailsInstaller/Ruby1.9.3/lib/ruby/gems/1.9.1/gems/minitest-4.7.5/lib/minitest/unit.rb:795:in `block in autorun'