Lifting the Curtain on Merge Conflict Resolution: A Sensemaking Perspective

Merge conflicts are an inevitable, but painful part of collaborative software development. Merge conflict resolution is nontrivial because it requires gathering information from disparate sources (e.g., a codebase, diffs between versions, history of changes, documentation etc.) and then piecing together not only this information, but the rationale and context behind the conflicting changes. Current tools offer inadequate support to developers trying to understand the context and impact of the conflicting changes. They also offer little support in evaluating potential resolutions. To improve conflict resolution tools, we first need to understand the information needs of conflict resolution and its underlying sensemaking process. In this paper, through in-situ observations of 10 conflict resolutions, we qualitatively investigate how developers collect and sensemake different conflict-related information and how they reach a resolution. We identified eight behaviour patterns that developers use. These patterns have implications for tool builders and developers alike. We identify specific areas that need improved tool support. We also highlight the sensemaking traps practitioners may fall into.