The impact of cross-distribution bug duplicates, empirical study on Debian and Ubuntu

Although open source distributions like Debian and Ubuntu are closely related, sometimes a bug reported in the Debian bug repository is reported independently in the Ubuntu repository as well, without the Ubuntu users nor developers being aware. Such cases of undetected cross-distribution bug duplicates can cause developers and users to lose precious time working on a fix that already exists or to work individually instead of collaborating to find a fix faster. We perform a case study on Ubuntu and Debian bug repositories to measure the amount of cross-distribution bug duplicates and estimate the amount of time lost. By adapting an existing within-project duplicate detection approach (achieving a similar recall of 60%), we find 821 cross-duplicates. The early detection of such duplicates could reduce the time lost by users waiting for a fix by a median of 38 days. Furthermore, we estimate that developers from the different distributions lose a median of 47 days in which they could have collaborated together, had they been aware of duplicates. These results show the need to detect and monitor cross-distribution duplicates.