Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/home/walle256/env/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
    utility.execute()
  File "/home/walle256/env/local/lib/python2.7/site-packages/django/core/management/__init__.py", line 354, in execute
    django.setup()
  File "/home/walle256/env/local/lib/python2.7/site-packages/django/__init__.py", line 21, in setup
    apps.populate(settings.INSTALLED_APPS)
  File "/home/walle256/env/local/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
    app_config.import_models(all_models)
  File "/home/walle256/env/local/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models
    self.models_module = import_module(models_module_name)
  File "/usr/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/home/walle256/env/local/lib/python2.7/site-packages/compressor/models.py", line 1, in <module>
    from compressor.conf import CompressorConf  # noqa
  File "/home/walle256/env/local/lib/python2.7/site-packages/compressor/conf.py", line 9, in <module>
    class CompressorConf(AppConf):
  File "/home/walle256/env/local/lib/python2.7/site-packages/appconf/base.py", line 75, in __new__
    new_class._configure()
  File "/home/walle256/env/local/lib/python2.7/site-packages/appconf/base.py", line 104, in _configure
    value = callback(value)
  File "/home/walle256/env/local/lib/python2.7/site-packages/compressor/conf.py", line 90, in configure_root
    'STATIC_ROOT, please define either')
django.core.exceptions.ImproperlyConfigured: COMPRESS_ROOT defaults to STATIC_ROOT, please define either