`aria-describedby`-Attribute missing from file field HTML in Django 6.0

[cessor]

In Django 6, input fields of type file do not render aria-describedby attributes. Those were introduced with Django 5.2. to facilitate use of screenreaders.

Steps to reproduce

• Create a model with a file = models.FileField(...)
• Render a forms.ModelForm for the model
• The HTML for the input field should contain attribute aria-describedby="id_file_helptext"
• When Django 5.2 is installed the attribute is rendered
• When Django 6.0 is installed, the attribute is not rendered

Note that this issue affects FileFields but not CharFields. Both render HTML input elements. I did not test whether other fields are also affected.

I attached a zipfile with an example app. To reproduce the error, please create a .venv and install Django 5.2, then run manage.py tests; all will succeed. When installing Django 6, one test will fail. The module web.tests contains two tests, both check the input field HTML for aria-describedby, one is for a charfield, the other for a filefield.

Details

Consider Issue #35892 "Supported Widget.use_fieldset in admin forms.". In the scope of this ticked, a change was made to django.forms.widgets.ClearableFileInput, where as with commit 4187da2 the value ClearableFileInput.use_fieldset is set to True by default.

Because of this change, django.forms.boundfield.BoundField.build_widget_attrs does not add the "aria-describedby" attribute to the attrs dictionary which is then missing from the final response HTML.

Sources:

• ​https://github.com/django/django/blame/0ca3a0661173b02e2cbb0183d8543e790e7e4a55/django/forms/widgets.py#L533
• ​https://github.com/django/django/blob/0ca3a0661173b02e2cbb0183d8543e790e7e4a55/django/forms/boundfield.py#L300