On Wasted Contributions: Understanding the Dynamics of Contributor-Abandoned Pull Requests

Pull-based development has enabled numerous volunteers to contribute open-source projects with fewer barriers. Nevertheless, a considerable amount of pull requests (PRs) valid contributions are abandoned by their contributors, wasting the effort and time put in both contributors maintainers. To better understand underlying dynamics contributor-abandoned PRs, we conduct mixed-methods study using quantitative qualitative methods. We curate dataset consisting 265,325 PRs including 4,450 ones from ten popular mature GitHub measure 16 features characterizing review processes, projects. Using statistical machine learning techniques, find that complex novice lengthy reviews have higher probability abandonment rate PR fluctuates alongside projects' maturity or workload. identify why abandon also manually examine random sample 354 PRs. observe most frequent reasons related obstacles faced followed hurdles imposed maintainers during process. Finally, survey top core studied perspectives on dealing our findings.