[Answer]-ValueError installing a python/django project

The add_to_builtins call in publicmarkup/urls.py is incorrect, it should probably be:

add_to_builtins('mediasync.templatetags.media')

Python packages are dot-delimited and the author used a path instead.

Later on, the Django framework tries to load the module, and splitting off the last name after the last dot fails as there are no dots in the original call.

It looks like the project you are trying to load is fundamentally broken. It probably will have other errors as well.