Towards automated debugging in software evolution: Evaluating delta debugging on real regression bugs from the developers' perspectives

We have evaluated two variants of delta debugging. Different from successful isolation in Zeller's initial studies, the results in our experiments vary wildly. Two thirds of isolated changes in studied programs provide direct or indirect clues in locating regression bugs. The remaining results are superfluous changes or even wrong isolations. In the case of wrong isolations, the isolated changes cause the same behaviour of the regression but are failure-irrelevant. Moreover, the hierarchical variant does not yield definite improvements in terms of the efficiency and accuracy.