  Code review consists of manual inspection, discussion, and judgment of source
code by developers other than the code's author. Due to discussions around
competing ideas and group decision-making processes, interpersonal conflicts
during code reviews are expected. This study systematically investigates how
developers perceive code review conflicts and addresses interpersonal conflicts
during code reviews as a theoretical construct. Through the thematic analysis
of interviews conducted with 22 developers, we confirm that conflicts during
code reviews are commonplace, anticipated and seen as normal by developers.
Even though conflicts do happen and carry a negative impact for the review,
conflicts-if resolved constructively-can also create value and bring
improvement. Moreover, the analysis provided insights on how strongly conflicts
during code review and its context (i.e., code, developer, team, organization)
are intertwined. Finally, there are aspects specific to code review conflicts
that call for the research and application of customized conflict resolution
and management techniques, some of which are discussed in this paper. Data and
material: https://doi.org/10.5281/zenodo.5848794
