"Error: Invalid user name dd-agent" during source install

[LotharSee]

Happened on FreeBSD.

Creating log file /home/benjamin/.datadog-agent/ddagent-install.log.....Done
Operating System: FreeBSD
Setting up virtual environment.....
[...]
New python executable in /home/benjamin/.datadog-agent/venv/bin/python
Installing setuptools............................done.
Installing pip...................done.
Done
Installing tornado 2.4.1 using pip.....Downloading/unpacking tornado==2.4.1
  Running setup.py egg_info for package tornado

    warning: no previously-included files matching '_auto2to3*' found anywhere in distribution
Installing collected packages: tornado
  Running setup.py install for tornado

    warning: no previously-included files matching '_auto2to3*' found anywhere in distribution
Successfully installed tornado
Cleaning up...
Done
Downloading the latest version of the agent from github (~2.5 MB)..... 
[...]
Done
Uncompressing the archive.....Done
Configuring datadog.conf file......Done
Setting up launching scripts.....Done
Setting up supervisor.....Downloading/unpacking supervisor
  Running setup.py egg_info for package supervisor

Requirement already satisfied (use --upgrade to upgrade): setuptools in ./.datadog-agent/venv/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg (from supervisor)
Downloading/unpacking meld3>=0.6.5 (from supervisor)
  Running setup.py egg_info for package meld3

Installing collected packages: supervisor, meld3
  Running setup.py install for supervisor

    Skipping installation of /home/benjamin/.datadog-agent/venv/lib/python2.7/site-packages/supervisor/__init__.py (namespace package)
    Installing /home/benjamin/.datadog-agent/venv/lib/python2.7/site-packages/supervisor-3.0b2-py2.7-nspkg.pth
    Installing echo_supervisord_conf script to /home/benjamin/.datadog-agent/venv/bin
    Installing pidproxy script to /home/benjamin/.datadog-agent/venv/bin
    Installing supervisorctl script to /home/benjamin/.datadog-agent/venv/bin
    Installing supervisord script to /home/benjamin/.datadog-agent/venv/bin
  Running setup.py install for meld3

Successfully installed supervisor meld3
Cleaning up...
Done
Consolidating logging.....Done
Cleaning up the installation directory.....Done
Starting the agent.....Error: Invalid user name dd-agent
For help, use /home/benjamin/.datadog-agent/venv/bin/supervisord -h
It looks like you hit an issue when trying to install the agent.
Failure when launching supervisor.