Predicting the Breakability of Blocking Bug Pairs

Software systems becomes increasingly complex for the wide use of social-software-development platforms, such as GitHub. Complicated inter-dependencies within ecosystems impose new challenges in resolving the blocking bug pairs, in which the upstream bugs prevent the downstream bugs to be fixed. Generally, the downstream bugs cannot be fixed until the upstream bugs are fixed in blocking bug pairs, which keeps the downstream developers waiting for a long time. However, previous research found that some blocking pairs could be "broken" through a workaround, i.e., a temporary solution proposed by the downstream developers before the upstream bugs get fixed. In this paper, we propose an approach to describe and predict the breakability of the blocking bug pairs. Our goal is to help the ecosystem developers to predict whether the given blocking bug pair can be broken. We evaluate our approach on two real world ecosystems: Mozilla Firefox and Netbeans, and have the following two main findings. First, the participants within the blocking bug pair and the vitality of the downstream bug have much impact on the breakability. Second, we can build breakability predication models with the accuracy of approximate 80%. Moreover, for predicting unbreakable pairs which affect the downstream projects seriously, our approach achieves a precision over 92%. It can be used to effectively remind the upstream developers to fix these bugs as quickly as possible.