ValueError: malformed node or string when attempting to rebase-migration

[jpsingleton]

When attempting python manage.py rebase-migration <app_label> during rebase conflict resolution:

Traceback (most recent call last):
  File "manage.py", line 58, in <module>
    run_django()
  File "manage.py", line 54, in run_django
    execute_from_command_line(argv)
  File "venv/lib/python3.8/site-packages/django/core/management/__init__.py", line 401, in execute_from_command_line
    utility.execute()
  File "venv/lib/python3.8/site-packages/django/core/management/__init__.py", line 395, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "venv/lib/python3.8/site-packages/django/core/management/base.py", line 328, in run_from_argv
    self.execute(*args, **cmd_options)
  File "venv/lib/python3.8/site-packages/django/core/management/base.py", line 369, in execute
    output = self.handle(*args, **options)
  File "venv/lib/python3.8/site-packages/django_linear_migrations/management/commands/rebase-migration.py", line 95, in handle
    dependencies = ast.literal_eval(deps)
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 99, in literal_eval
    return _convert(node_or_string)
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 82, in _convert
    return list(map(_convert, node.elts))
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 98, in _convert
    return _convert_signed_num(node)
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 75, in _convert_signed_num
    return _convert_num(node)
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 66, in _convert_num
    _raise_malformed_node(node)
  File ".pyenv/versions/3.8.8/lib/python3.8/ast.py", line 63, in _raise_malformed_node
    raise ValueError(f'malformed node or string: {node!r}')
ValueError: malformed node or string: <_ast.Call object at 0x7fe9727b9850>

[adamchainz]

Would need to see the contents of the migration file to see the bug here - can you send that to me privately?

[adamchainz]

This issue was caused by a swappable dependency on the user model setting:

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
        ("example", ".."),
    ]

I guess we really need to use a full ast parse, rather than assuming it will work as a literal.