Error building commcarehq_incl to run HQ in Docker

[polyakov]

I am following instructions on https://github.com/dimagi/commcare-hq/blob/master/docker/README.rst and the command docker build -f Dockerfile_incl -t commcarehq_incl . fails on the very last command in the Dockerfile_incl:

 => ERROR [17/17] RUN python manage.py collectstatic --noinput                                                                                                                                              0.9s
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 > [17/17] RUN python manage.py collectstatic --noinput:
#27 0.811 fatal: not a git repository (or any of the parent directories): .git

Any advice would be greatly appreciated. Thank you.