Modelo do Django: ValueError: Entrada de manifesto de arquivos estáticos ausentes para "file_name.ext"

Antes de marcá-lo como duplicado, liValueError: Entrada de manifesto de arquivos estáticos ausente para 'favicon.ico', e não resolve o meu problema.

Eu tenho o seguinte modelo:

from django.contrib.staticfiles.templatetags.staticfiles import static

class Profile(models.Model):
    user = models.ForeignKey(SocialUser, on_delete=models.PROTECT)
    avatar_url = models.URLField(
        default=static('pledges/images/no-profile-photo.png'))

Estou usando o Codeship for CI e quando executo:

$ python manage.py collectstatic --noinput

Eu estou recebendo o seguinte erro:

Traceback (most recent call last):
File "manage.py", line 22, in <module>
execute_from_command_line(sys.argv)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
utility.execute()
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/core/management/__init__.py", line 338, in execute
django.setup()
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/__init__.py", line 27, in setup
apps.populate(settings.INSTALLED_APPS)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/apps/registry.py", line 108, in populate
app_config.import_models()
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/apps/config.py", line 202, in import_models
self.models_module = import_module(models_module_name)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/importlib/__init__.py", line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 994, in _gcd_import
File "<frozen importlib._bootstrap>", line 971, in _find_and_load
File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 665, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 678, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/home/rof/src/github.com/company-name/project-name/pledges/models.py", line 106, in <module>
class Profile(models.Model):
File "/home/rof/src/github.com/company-name/project-name/pledges/models.py", line 109, in Profile
default=static('pledges/images/no-profile-photo.png'))
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/contrib/staticfiles/templatetags/staticfiles.py", line 12, in static
return _static(path)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/templatetags/static.py", line 166, in static
return StaticNode.handle_simple(path)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/templatetags/static.py", line 117, in handle_simple
return staticfiles_storage.url(path)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/contrib/staticfiles/storage.py", line 162, in url
return self._url(self.stored_name, name, force)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/contrib/staticfiles/storage.py", line 141, in _url
hashed_name = hashed_name_func(*args)
File "/home/rof/.pyenv/versions/3.6/lib/python3.6/site-packages/django/contrib/staticfiles/storage.py", line 432, in stored_name
raise ValueError("Missing staticfiles manifest entry for '%s'" % clean_name)
ValueError: Missing staticfiles manifest entry for 'pledges/images/no-profile-photo.png'

Não estou tendo problemas localmente, então me pergunto o que está causando esse problema e como resolvê-lo. O que eu entendo no código é que não posso usar a funçãostatic&nbsp;para um campo de modelo.

Alguém tem alguma idéia de como descobrir isso? Alguém pode me explicar por que isso está acontecendo?