Why Is My Bug Wontfix?

Developers often use bug reports to triage and fix bugs. However, not every bug can be fixed eventually. To understand the underlying reasons why bugs are wontfix, we conduct an empirical study on three open source projects (i.e., Mozilla, Eclipse and Apache OpenOffice) in Bugzilla. First, we manually analyzed 600 wontfix bug reports. Second, we used the open card sorting approach to label these bug reports why they were wontfix, and we summarized 12 categories of reasons. Next, we further studied the frequency distribution of the categories across projects. We found that Not Support bug reports are the majority of the wontfix bug reports. Moreover, the frequency distribution of wontfix bug reports across the 12 categories is basically similar for the three open source projects.