CI job trips on Apache Superset 2.x: AttributeError: module 'flask.json' has no attribute 'JSONEncoder'

[amotl]

Problem

Invoking superset db upgrade fails.

-- https://github.com/crate/cratedb-examples/actions/runs/8005637022/job/21865556761#step:7:290

History

It failed for the first time on Tue, 20 Feb 2024 03:06:45 GMT. Before, it worked well, and nothing was changed on our ends.

-- https://github.com/crate/cratedb-examples/actions/workflows/application-apache-superset.yml

[amotl]

Root cause

The traceback is:

Traceback (most recent call last):
  File "/path/to/bin/superset", line 5, in <module>
    from superset.cli.main import superset
  File "/path/to/lib/python3.11/site-packages/superset/__init__.py", line 21, in <module>
    from superset.app import create_app
  File "/path/to/lib/python3.11/site-packages/superset/app.py", line 23, in <module>
    from superset.initialization import SupersetAppInitializer
  File "/path/to/lib/python3.11/site-packages/superset/initialization/__init__.py", line 27, in <module>
    from flask_appbuilder import expose, IndexView
  File "/path/to/lib/python3.11/site-packages/flask_appbuilder/__init__.py", line 5, in <module>
    from .api import ModelRestApi  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/lib/python3.11/site-packages/flask_appbuilder/api/__init__.py", line 38, in <module>
    from ..baseviews import AbstractViewApi
  File "/path/to/lib/python3.11/site-packages/flask_appbuilder/baseviews.py", line 22, in <module>
    from .forms import GeneralModelConverter
  File "/path/to/lib/python3.11/site-packages/flask_appbuilder/forms.py", line 3, in <module>
    from flask_wtf import FlaskForm
  File "/path/to/lib/python3.11/site-packages/flask_wtf/__init__.py", line 4, in <module>
    from .recaptcha import Recaptcha
  File "/path/to/lib/python3.11/site-packages/flask_wtf/recaptcha/__init__.py", line 1, in <module>
    from .fields import RecaptchaField
  File "/path/to/lib/python3.11/site-packages/flask_wtf/recaptcha/fields.py", line 3, in <module>
    from . import widgets
  File "/path/to/lib/python3.11/site-packages/flask_wtf/recaptcha/widgets.py", line 6, in <module>
    JSONEncoder = json.JSONEncoder
                  ^^^^^^^^^^^^^^^^
AttributeError: module 'flask.json' has no attribute 'JSONEncoder'

References

• Flask2.3.X JSONEncoder deprecated MongoEngine/flask-mongoengine#522
• puppetboard fails to start because module 'flask.json' has no attribute 'JSONEncoder' voxpupuli/puppetboard#888
• package conflicts aptible/deploy-demo-app#37
• AttributeError: module 'flask.json' has no attribute 'JSONEncoder' czbiohub-sf/excellxgene#20
• Failure to run after install cs91chris/flask_autocrud#7

[amotl]

Downgrading to Flask 2.2, using pip install 'flask<2.3', as suggested, apparently resolves the problem, but then trips with a totally different error:

ERROR [flask_migrate] Error: Can't locate revision identified by 'b7851ee5522f'

[amotl]

I can't discover the root cause, so I've reported it to upstream.

• Superset 2.x: AttributeError: module 'flask.json' has no attribute 'JSONEncoder' apache/superset#27204

[amotl]

The upstream issue has been converted into a discussion, because Apache Superset 2.x is not supported any longer. Thanks, @michael-s-molina.

• Superset 2.x: `AttributeError: module 'flask.json' has no attribute 'JSONEncoder'` apache/superset#27211

/cc @proddata

[amotl]

GH-335 will remove testing of Apache Superset 2.x on CI.