【Django】ValueError: The field admin.LogEntry.user was declared with a lazy reference to...

###実現したいこと
Userモデルをmigrateしたい。

エラーの意味だけでも分かったら教えていただきたいです。

###発生しているエラー
ValueError: The field admin.LogEntry.user was declared with a lazy reference to 'polls.user', but app 'polls' doesn't provide model 'user'.

以下のUserモデルを追加すると、makemigrationsはできるけれどmigrateができず、上記のエラーが出ます。

上記のエラーで検索すると、migrationファイルを全て消すと動くみたいなことが書かれていたので、アプリケーションを一から作り直しましたがうまくいきませんでした。ちなみにsetttings.pyに
AUTH_USER_MODEL = "polls.User"
は追加しています。

app 'polls' doesn't provide model 'user' の部分が引っかかるのですが、意味だけでも分かったら教えてください。

###該当のソースコード

Python
1# models.py
2class MyUserManager(UserManager):
3    use_in_migrations = True
4
5    def _create_user(self, username, email, password, **extra_fields):
6        if not username:
7            raise ValueError("The given username must be set")
8        email = self.normalize_email(email)
9        username = self.model.normalize_username(username)
10        user = self.model(username=username, email=email, **extra_fields)
11        user.set_password(password)
12        user.save(using=self._db)
13        return user
14
15    def create_user(self, username, email=None, password=None, **extra_fields):
16        extra_fields.setdefault("is_staff", False)
17        extra_fields.setdefault("is_superuser", False)
18        return self._create_user(username, email, password, **extra_fields)
19
20    def create_superuser(self, username, email=None, password=None, **extra_fields):
21        extra_fields.setdefault("is_staff", True)
22        extra_fields.setdefault("is_superuser", True)
23
24        if extra_fields.get("is_staff") is not True:
25            raise ValueError("Superuser must have is_staff=True.")
26        if extra_fields.get("is_superuser") is not True:
27            raise ValueError("Superuser must have is_superuser=True.")
28
29        return self._create_user(username, email, password, **extra_fields)
30
31
32class User(AbstractBaseUser, PermissionsMixin):
33
34    username_validator = UnicodeUsernameValidator()
35
36    username = models.CharField(
37        _("username"),
38        max_length=30,
39        unique=True,
40        default="nanashi",
41        help_text=_(
42            "Required. 30 characters or fewer. Letters, digits and @/./+/-/_ only."
43        ),
44        validators=[username_validator],
45        error_messages={"unique": _("A user with that username already exists."),},
46    )
47    first_name = models.CharField(_("first name"), max_length=30,)
48    last_name = models.CharField(_("last name"), max_length=30,)
49    email = models.EmailField(_("email address"), unique=True)
50
51    is_staff = models.BooleanField(
52        _("staff status"),
53        default=False,
54        help_text=_("Designates whether the user can log into this admin site."),
55    )
56    is_active = models.BooleanField(
57        _("active"),
58        default=True,
59        help_text=_(
60            "Designates whether this user should be treated as active. "
61            "Unselect this instead of deleting accounts."
62        ),
63    )
64    date_joined = models.DateTimeField(_("date joined"), default=timezone.now)
65
66    objects = MyUserManager()
67
68    EMAIL_FIELD = "email"
69    USERNAME_FIELD = "username"
70    REQUIRED_FIELDS = ["email"]
71
72    class Meta:
73        verbose_name = _("user")
74        verbose_name_plural = _("users")
75
76    def get_full_name(self):
77        full_name = "%s %s" % (self.first_name, self.last_name)
78        return full_name.strip()
79
80    def get_short_name(self):
81        return self.first_name
82
83    def email_user(self, subject, message, from_email=None, **kwargs):
84        send_mail(subject, message, from_email, [self.email], **kwargs)