the opencv 2.4.9 test failed with Video_calcOpticalFlowDual_TVL1.Regression

edit

Here is the fail message:

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#opencv_test_video
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[ RUN      ] Video_calcOpticalFlowDual_TVL1.Regression
/home/dracula/mytmp/opencv/modules/video/test/test_tvl1optflow.cpp:169: Failure
Expected: (err) <= (MAX_RMSE), actual: 0.0207956 vs 0.02
[  FAILED  ] Video_calcOpticalFlowDual_TVL1.Regression (1069 ms)

compiled with gcc 4.8.3

-DENABLE_FAST_MATH:BOOL="1" 
-DENABLE_AVX:BOOL="1" 
-DENABLE_COVERAGE:BOOL="1"
-DWITH_OPENGL:BOOL="1" 
-DWITH_QT:BOOL="1" 
-DWITH_TBB:BOOL="1"

versions:

opencv: f8758da289c092fcce10baa4723d6388c4e41cb3 2.4.9.x-prep

opencv_extra: 61d59fcaa8d3cebb05ae6eadf0ab8cc5ac597445 tags/2.4.9

Can anyone tell me if this is because I used wrong opencv_extra version? Which version I should use?