RuntimeError: Conflicting 'product_product_options' models in application 'catalogue'

[Bhaskar Chaudhary]

Version Info: Python 3.4, Django 1.8, Oscar Commerce - VERSION = (1, 2, 1, 'final')

I am trying to customize Products in the catalogue app following the documentation.

Having forked the catalogue app, I have defined models.py as follows:

from django.db import models
from oscar.apps.catalogue.abstract_models import AbstractProduct

class Product(AbstractProduct):
 is_active = models.BooleanField(default=False)

from oscar.apps.catalogue.models import *

I have already included the modified catalogue, in the INSTALLED_APPS in settings.py as a list, as suggested for a similar problem here.

INSTALLED_APPS = INSTALLED_APPS + get_core_apps( ['app.gravytrain.catalogue',])

Have copied the migration folder from oscar/apps/catalogue to my custom app. However running migration causes the following error:

RuntimeError: Conflicting 'product_product_options' models in
application 'catalogue': <class 'gravytrain.catalogue.models.Product_product_options'> and <class
app.gravytrain.catalogue.models.Product_product_options'>.

How do I get over this error ?