The file command changed its MIME type for empty files.

test/io_adapters/file_adapter_test.rb

@@ -91,7 +91,7 @@ class FileAdapterTest < Test::Unit::TestCase
       teardown { @file.close }
       teardown { @file.close }
 
 
       should "provide correct mime-type" do
       should "provide correct mime-type" do
-        assert_equal "application/x-empty", @subject.content_type
+        assert_match %r{.*/x-empty}, @subject.content_type
       end
       end
     end
     end
   end
   end