Ensure REPO_DIR owned by NB_USER

repo2docker/buildpacks/base.py

@@ -113,6 +113,7 @@ COPY --chown={{ user }}:{{ user }} {{ src }} {{ dst }}
 ARG REPO_DIR=${HOME}
 ENV REPO_DIR ${REPO_DIR}
 WORKDIR ${REPO_DIR}
+RUN chown ${NB_USER}:${NB_USER} ${REPO_DIR}
 
 # We want to allow two things:
 #   1. If there's a .local/bin directory in the repo, things there