I am trying to deploy mediagoblin on a Raspberry Pi 3B+ according to the instructions found on https://mediagoblin.readthedocs.io/en/stable/siteadmin/deploying.html (the Python 3 variant). I've tried on both Raspbian Buster and Ubuntu MATE 18.04.2, but they both fail in the same place, as shown below.
mediagoblin@pi-mate:/srv/mediagoblin.example.org/mediagoblin$ ./bin/gmg dbupdate
Traceback (most recent call last):
File "./bin/gmg", line 11, in <module>
load_entry_point('mediagoblin', 'console_scripts', 'gmg')()
File "/srv/mediagoblin.example.org/mediagoblin/mediagoblin/gmg_commands/__init__.py", line 148, in main_cli
args.func(args)
File "/srv/mediagoblin.example.org/mediagoblin/mediagoblin/gmg_commands/dbupdate.py", line 235, in dbupdate
global_config, app_config = setup_global_and_app_config(args.conf_file)
File "/srv/mediagoblin.example.org/mediagoblin/mediagoblin/init/__init__.py", line 48, in setup_global_and_app_config
global_config, validation_result = read_mediagoblin_config(config_path)
File "/srv/mediagoblin.example.org/mediagoblin/mediagoblin/init/config.py", line 89, in read_mediagoblin_config
mainconfig_defaults = copy.copy(config_spec.get("DEFAULT", {}))
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/copy.py", line 96, in copy
rv = reductor(4)
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 482, in __reduce__
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 557, in __getitem__
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 549, in _interpolate
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 352, in interpolate
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 330, in recursive_interpolate
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 417, in _parse_match
File "/srv/mediagoblin.example.org/mediagoblin/lib/python3.6/site-packages/configobj-5.0.6-py3.6.egg/configobj.py", line 386, in _fetch
configobj.MissingInterpolationOption: missing option "here" in interpolation.
All of the steps leading up to that have executed successfully. Any ideas what could be the issue?