get_for_model() method on ObjectType manager does not reliably resolve instances to classes #1422

New Issue

MrUnknownDE · 2026-04-06T01:09:50+02:00

MrUnknownDE commented

2026-04-06 01:09:50 +02:00

Originally created by @jeremystretch on 8/20/2025

Deployment Type

Self-hosted

NetBox Version

v4.4.0-beta1

Python Version

3.10

Steps to Reproduce

Reproduction for this is a bit contrived, as the issue surfaced during the application of migrations under niche circumstances, but ultimately it derives from calling ObjectType.objects.get_for_model(model) when an ObjectType record for the given model does not yet exist.

Expected Behavior

A new ObjectType record should be automatically created for the model.

Observed Behavior

An exception is raised:

AttributeError: type object 'ModelBase' has no attribute '_meta'

This is due to forcing resolution of the base class (line 78):

a59da37ac3/netbox/core/models/object_types.py (L74-L79)

*Originally created by @jeremystretch on 8/20/2025* ### Deployment Type Self-hosted ### NetBox Version v4.4.0-beta1 ### Python Version 3.10 ### Steps to Reproduce Reproduction for this is a bit contrived, as the issue surfaced during the application of migrations under niche circumstances, but ultimately it derives from calling `ObjectType.objects.get_for_model(model)` when an ObjectType record for the given model does not yet exist. ### Expected Behavior A new ObjectType record should be automatically created for the model. ### Observed Behavior An exception is raised: ``` AttributeError: type object 'ModelBase' has no attribute '_meta' ``` This is due to forcing resolution of the base class (line 78): https://github.com/netbox-community/netbox/blob/a59da37ac3a41ed40b361dac3a1b17312a887076/netbox/core/models/object_types.py#L74-L79

MrUnknownDE closed this issue

2026-04-06 01:09:50 +02:00

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Branches Tags

main

21455-sql-indexes-audit

21357-register-model-actions

feature

20924-plugin-ui-components

21766-improve-test-coverage-for-sortable-table-columns

21157-export-template-public-models

21025-pre-render-config-contexts

21364-swagger

feature-ip-prefix-link

20911-dropdown-3

fix_module_substitution

21160-filterset

20911-dropdown-2

20044-elevation-stuck-lightmode

7604-filter-modifiers-v3

20660-script-load

19724-graphql

14884-script

19720-macaddress-interface-generic-relation

fix-19669-api-image-download

7604-filter-modifiers

19275-fixes-interface-bulk-edit

fix-17794-get_field_value_return_list

11507-show-aggregate-and-rir-on-api

9583-add_column_specific_search_field_to_tables

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Reference: github/netbox#1422

get_for_model() method on ObjectType manager does not reliably resolve instances to classes #1422