~/workspace$ pythn manage.py makemigrations customers
bash: pythn: command not found
~/workspace$ python manage.py makemigrations customers
Was the model customers.Package renamed to Service? [y/N] y
Was invoice.package renamed to invoice.service (a ForeignKey)? [y/N] y
Was invoice.package_amount renamed to invoice.service_amount (a DecimalField)? [y/N] 
Was serviceperiod.package renamed to serviceperiod.service (a ForeignKey)? [y/N] 
Was customer.package renamed to customer.service (a ForeignKey)? [y/N] 
It is impossible to add a non-nullable field 'service_amount' to invoice without specifying a default. This is because the database needs something to populate existing rows.
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit and manually define a default value in models.py.
Select an option: 
Please select a valid option: 
Please select a valid option: 
Please select a valid option: 1   
Please enter the default value as valid Python.
The datetime and django.utils.timezone modules are available, so it is possible to provide e.g. timezone.now as a value.
Type 'exit' to exit this prompt
>>> '1000'
It is impossible to add a non-nullable field 'service' to serviceperiod without specifying a default. This is because the database needs something to populate existing rows.
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit and manually define a default value in models.py.
Select an option: '1 month'
Please select a valid option: 1
Please enter the default value as valid Python.
The datetime and django.utils.timezone modules are available, so it is possible to provide e.g. timezone.now as a value.
Type 'exit' to exit this prompt
>>> '1 month'
Migrations for 'billing':
  billing/migrations/0003_rename_package_invoice_service_and_more.py
    - Rename field package on invoice to service
    - Remove field package_amount from invoice
    - Remove field package from serviceperiod
    - Add field service_amount to invoice
    - Add field service to serviceperiod
Migrations for 'customers':
  customers/migrations/0006_rename_package_service_alter_service_options_and_more.py
    - Rename model Package to Service
    - Change Meta options on service
    - Remove field package from customer
    - Add field service to customer
~/workspace$ python manage.py migrate
Operations to perform:
  Apply all migrations: accounts, admin, auth, billing, contenttypes, customers, hr, network, notifications, payments, sessions, settings, tickets
Running migrations:
  Applying billing.0003_rename_package_invoice_service_and_more...Traceback (most recent call last):
  File "/home/runner/workspace/manage.py", line 22, in <module>
    main()
  File "/home/runner/workspace/manage.py", line 18, in main
    execute_from_command_line(sys.argv)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/__init__.py", line 442, in execute_from_command_line
    utility.execute()
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/__init__.py", line 436, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/base.py", line 413, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/base.py", line 459, in execute
    output = self.handle(*args, **options)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/base.py", line 107, in wrapper
    res = handle_func(*args, **kwargs)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/core/management/commands/migrate.py", line 356, in handle
    post_migrate_state = executor.migrate(
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/migrations/executor.py", line 135, in migrate
    state = self._migrate_all_forwards(
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/migrations/executor.py", line 167, in _migrate_all_forwards
    state = self.apply_migration(
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/migrations/executor.py", line 252, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/migrations/migration.py", line 132, in apply
    operation.database_forwards(
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/migrations/operations/fields.py", line 108, in database_forwards
    schema_editor.add_field(
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/backends/sqlite3/schema.py", line 316, in add_field
    self._remake_table(model, create_field=field)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/backends/sqlite3/schema.py", line 145, in _remake_table
    self.effective_default(create_field)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/backends/base/schema.py", line 466, in effective_default
    return field.get_db_prep_save(self._effective_default(field), self.connection)
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/backends/base/schema.py", line 442, in _effective_default
    default = field.get_default()
  File "/home/runner/workspace/.pythonlibs/lib/python3.10/site-packages/django/db/models/fields/related.py", line 1135, in get_default
    if isinstance(field_default, self.remote_field.model):
TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union