fails:IO#close_on_exec? returns true by default
fails(windows):IO#close_on_exec= returns false from #respond_to?
fails(windows):IO#close_on_exec= raises a NotImplementedError when called
fails(windows):IO#close_on_exec? returns false from #respond_to?
fails(windows):IO#close_on_exec? raises a NotImplementedError when called
