The assessment of repository evolution is particularly complex when one needs to analyze both 1) how the codebase is organized hierarchically and 2) how this codebase evolves over time. To address this problem, we developed Git Truck, a visualization tool that includes multiple views for the analysis of the evolution of hierarchically organized Git repositories. We conducted a preliminary user evaluation with 18 participants who, using a remote and asynchronous method, installed Git Truck, used it, and filled in a questionnaire to report their experience and impressions. We learned that participants consider particularly useful views that help them with understanding the contribution level of team members and views that highlight the parts of the system that change the most. The participants see Git Truck as a highly specialized tool; not for daily use but rather for a lower frequency of use.