2.5.0 to 2.6.0 error: TypeError: issubclass() arg 1 must be a class

[kayluhb]

Hello,

Thanks for all the work on the new release.

I am however getting this error when upgrading to 2.6.0 from 2.5.0 and I just wanted to make sure I understand the change.

 Traceback (most recent call last):
   File "src/manage.py", line 22, in <module>
     execute_from_command_line(sys.argv)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
     utility.execute()
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
     self.fetch_command(subcommand).run_from_argv(self.argv)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/base.py", line 323, in run_from_argv
     self.execute(*args, **cmd_options)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/base.py", line 361, in execute
     self.check()
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/base.py", line 390, in check
     include_deployment_checks=include_deployment_checks,
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 65, in _run_checks
     issues.extend(super()._run_checks(**kwargs))
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/management/base.py", line 377, in _run_checks
     return checks.run_checks(**kwargs)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/core/checks/registry.py", line 72, in run_checks
     new_errors = check(app_configs=app_configs)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/contrib/admin/checks.py", line 111, in check_dependencies
     if not _contains_subclass('django.contrib.auth.middleware.AuthenticationMiddleware', settings.MIDDLEWARE):
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/contrib/admin/checks.py", line 43, in _contains_subclass
     candidate_cls = import_string(path)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/django/utils/module_loading.py", line 17, in import_string
     module = import_module(module_path)
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/importlib/__init__.py", line 127, in import_module
     return _bootstrap._gcd_import(name[level:], package, level)
   File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
   File "<frozen importlib._bootstrap>", line 983, in _find_and_load
   File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
   File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
   File "<frozen importlib._bootstrap_external>", line 728, in exec_module
   File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
   File "/app/src/ems_api/middleware.py", line 5, in <module>
     from ems.schema import loaders as ems_loaders, nodes
   File "/app/src/ems/schema/nodes.py", line 44, in <module>
     class BenefitSetNode(graphene_django.DjangoObjectType):
   File "/app/src/ems/schema/nodes.py", line 48, in BenefitSetNode
     benefits = fields.DjangoListField("ems.schema.nodes.BenefitNode")
   File "/root/.local/share/virtualenvs/app-4PlAip0Q/lib/python3.7/site-packages/graphene_django/fields.py", line 23, in __init__
     _type, DjangoObjectType
 TypeError: issubclass() arg 1 must be a class

Does this mean I can no longer pass strings into DjangoListField?

e.g. benefits = fields.DjangoListField("ems.schema.nodes.BenefitNode")

[NateScarlet]

This should caused by #732 .
Don't know why dynamic type support is dropped for DjangoListField.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[zbyte64]

Wasn't aware this was a feature at one point. Reopening for now, we should open an issue to make this an official feature/enhancement with unit testing.

[jkimbo]

I also didn't realise that that was a feature! I've created PR to fix it: #885

Sorry for the inconvenience @kayluhb and thanks @NateScarlet for figuring out the case, it made fixing it very easy.