Avoid username field creation in user model

[TotallyNotChase]

I'm using a custom user model with allauth and I need to have the username field omitted. I've already seen the docs and a whole bunch of stackoverflow answers about using ACCOUNT_USER_MODEL_USERNAME_FIELD = None but all of this still leads my database to have an username field.

Now since the db still has an username field with the unique constraint set on and allauth will not put a username in the field with the aforementioned setting set to None, this causes me to face IntegrityError after the very first user creation. I know I can solve this by just having the aforementioned setting be set to 'username' but I'm curious, how do I just not make the username, because I'm never using it.

My model:

class CustomUser(AbstractUser):
    # Custom user model for django-allauth
    first_name = None
    last_name = None

    def delete(self):
        # Custom delete - make sure user storage is also purged
        # Purge the user storage
        purge_userstore(self.email)
        # Call the original delete method to take care of everything else
        super(CustomUser, self).delete()

It doesn't really do much except override the delete function. It also sets first_name and last_name to None, which works perfectly and removes those fields from the database as expected. I've tried setting user to None but that does nothing. I've also tried setting username to None but that will raise a FieldNotFound error with ACCOUNT_USER_MODEL_USERNAME_FIELD = None

My settings (the relevant bit):

AUTHENTICATION_BACKENDS = (
    "django.contrib.auth.backends.ModelBackend",
    "allauth.account.auth_backends.AuthenticationBackend",
)
AUTH_USER_MODEL = 'custom_account.CustomUser'
ACCOUNT_USER_MODEL_USERNAME_FIELD = None
ACCOUNT_USERNAME_REQUIRED = False
ACCOUNT_EMAIL_REQUIRED = True
ACCOUNT_UNIQUE_EMAIL = True
ACCOUNT_AUTHENTICATION_METHOD = 'email'

My migration file:

migrations.CreateModel(
            name='CustomUser',
            fields=[
                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                ('password', models.CharField(max_length=128, verbose_name='password')),
                ('last_login', models.DateTimeField(blank=True, null=True, verbose_name='last login')),
                ('is_superuser', models.BooleanField(default=False, help_text='Designates that this user has all permissions without explicitly assigning them.', verbose_name='superuser status')),
                ('username', models.CharField(error_messages={'unique': 'A user with that username already exists.'}, help_text='Required. 150 characters or fewer. Letters, digits and @/./+/-/_ only.', max_length=150, unique=True, validators=[django.contrib.auth.validators.UnicodeUsernameValidator()], verbose_name='username')),
                ('email', models.EmailField(blank=True, max_length=254, verbose_name='email address')),
                ('is_staff', models.BooleanField(default=False, help_text='Designates whether the user can log into this admin site.', verbose_name='staff status')),
                ('is_active', models.BooleanField(default=True, help_text='Designates whether this user should be treated as active. Unselect this instead of deleting accounts.', verbose_name='active')),
                ('date_joined', models.DateTimeField(default=django.utils.timezone.now, verbose_name='date joined')),
                ('groups', models.ManyToManyField(blank=True, help_text='The groups this user belongs to. A user will get all permissions granted to each of their groups.', related_name='user_set', related_query_name='user', to='auth.Group', verbose_name='groups')),
                ('user_permissions', models.ManyToManyField(blank=True, help_text='Specific permissions for this user.', related_name='user_set', related_query_name='user', to='auth.Permission', verbose_name='user permissions')),
            ],
....

This migration generation confuses me to no end. Why is the username field still there? Why is it set to be the only unique constraint even though I've clearly set ACCOUNT_UNIQUE_EMAIL = True?

At first I thought, my settings were simply not being read. But I checked django.conf.settings and allauth.account.app_settings for these changes and they were all updated. What's going on here?

[TotallyNotChase]

Note: I have already ran makemigrations many times with many changes (after deleting all the previous migrations), I cannot seem to get rid of username no matter what I try

[pennersr]

The username column is not created by alllauth, you can find it inside Django's abstract user:

https://docs.djangoproject.com/en/3.0/topics/auth/customizing/#django.contrib.auth.models.AbstractBaseUser