{"action":"created","issue":{"url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/3","labels_url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/3/labels{/name}","comments_url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/3/comments","events_url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/3/events","html_url":"https://github.com/craigds/django-fieldsignals/issues/3","id":105537245,"number":3,"title":"have a 'many to many' field in signal, go wrong","user":{"login":"Thomas-23","id":4883171,"avatar_url":"https://avatars.githubusercontent.com/u/4883171?v=3","gravatar_id":"","url":"https://api.github.com/users/Thomas-23","html_url":"https://github.com/Thomas-23","followers_url":"https://api.github.com/users/Thomas-23/followers","following_url":"https://api.github.com/users/Thomas-23/following{/other_user}","gists_url":"https://api.github.com/users/Thomas-23/gists{/gist_id}","starred_url":"https://api.github.com/users/Thomas-23/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Thomas-23/subscriptions","organizations_url":"https://api.github.com/users/Thomas-23/orgs","repos_url":"https://api.github.com/users/Thomas-23/repos","events_url":"https://api.github.com/users/Thomas-23/events{/privacy}","received_events_url":"https://api.github.com/users/Thomas-23/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":7,"created_at":"2015-09-09T07:43:11Z","updated_at":"2015-10-20T09:05:15Z","closed_at":null,"body":"i have model\r\n```python\r\n@python_2_unicode_compatible\r\nclass CustomUser(InformationModel):\r\n    platform = models.ManyToManyField(Platform, verbose_name='box')\r\n    user = models.OneToOneField(User, primary_key=True, on_delete=models.CASCADE)\r\n```\r\nthen i want listen 'platform' field changed signal\r\n```python\r\ndef update_platforms_caches(sender, instance, **kwargs):\r\n    logger.info('*************plat_form_changed************')\r\npost_save_changed.connect(update_platforms_caches, sender=models.CustomUser, fields=['platform'])\r\n```\r\nbut it went wrong after i gone this,  it is a bug or i need to do some other steps to solve this, the error info is:\r\n```\r\nRequest Method:\tGET\r\nRequest URL:\thttp://127.0.0.1:8000/admin/auth/user/1/\r\nDjango Version:\t1.8.1\r\nException Type:\tValueError\r\nException Value:\t\r\n\"<CustomUser: >\" needs to have a value for field \"customuser\" before this many-to-many relationship can be used.\r\nException Location:\tE:\\working\\jiayuan\\django_tool_env3\\lib\\site-packages\\django\\db\\models\\fields\\related.py in __init__, line 874\r\nPython Executable:\tE:\\working\\jiayuan\\django_tool_env3\\Scripts\\python.exe\r\nPython Version:\t3.4.3\r\n```\r\n\r\nthank you for your open source"},"comment":{"url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/comments/149485757","html_url":"https://github.com/craigds/django-fieldsignals/issues/3#issuecomment-149485757","issue_url":"https://api.github.com/repos/craigds/django-fieldsignals/issues/3","id":149485757,"user":{"login":"tykling","id":1965355,"avatar_url":"https://avatars.githubusercontent.com/u/1965355?v=3","gravatar_id":"","url":"https://api.github.com/users/tykling","html_url":"https://github.com/tykling","followers_url":"https://api.github.com/users/tykling/followers","following_url":"https://api.github.com/users/tykling/following{/other_user}","gists_url":"https://api.github.com/users/tykling/gists{/gist_id}","starred_url":"https://api.github.com/users/tykling/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tykling/subscriptions","organizations_url":"https://api.github.com/users/tykling/orgs","repos_url":"https://api.github.com/users/tykling/repos","events_url":"https://api.github.com/users/tykling/events{/privacy}","received_events_url":"https://api.github.com/users/tykling/received_events","type":"User","site_admin":false},"created_at":"2015-10-20T09:05:15Z","updated_at":"2015-10-20T09:05:15Z","body":"I have the same problem. Is there a fix for fieldsignals and m2m fields coming or is there a workaround?"}}