ValueError: ('Duplicate name', 'IDublinCore.creators')

Plone 5.2.1

Adding a Plone-addon with these behaviors seems to break Plone completely:

Traceback (innermost last):
  Module ZServer.ZPublisher.Publish, line 144, in publish
  Module ZPublisher.mapply, line 85, in mapply
  Module ZServer.ZPublisher.Publish, line 44, in call_object
  Module plone.z3cform.layout, line 63, in __call__
  Module plone.z3cform.layout, line 47, in update
  Module plone.dexterity.browser.add, line 141, in update
  Module plone.z3cform.fieldsets.extensible, line 64, in update
  Module plone.autoform.form, line 34, in updateFields
  Module plone.autoform.base, line 117, in updateFieldsFromSchemata
  Module plone.autoform.utils, line 287, in processFields
  Module plone.autoform.utils, line 170, in _process_fieldsets
  Module z3c.form.util, line 298, in __add__
  Module z3c.form.field, line 136, in __init__
ValueError: ('Duplicate name', 'IDublinCore.creators')

This worked in Plone 5.2.0 without issues, broken in 5.2.1...anything I am missing here?

I bet among the behaviors you also have plone.dublincore... that might cause the issue.
If this is the case could you please file an issue on Github.

Thank you for breaking things and reporting ;)!

Well, thanks Plone for breaking things between 5.2.0 and 5.2.1 :sleepy:

This is interesting. I only saw this together with zope.interface master branch and thought its a problem there. Do you have some special version pinning or checkouts?

Nope

Using the test buildout cfg

I also ran into this error on a dockerized Plone 5.0.8 site, after rebuilding the image, that was supposed to be bullet proof..
Jens gave the right hint, it depends on zope.interface, especially if you use 'zope.interface =' in versions section of your buildout.cfg
In this case Plone gets a more recent version of zope.interface (4.7.1 instead of) and it will break the site.
Solution: Avoid using 'zope.interface =' or pin it to the correct version.

I already fixed plone.supermodel master, so this should be fixed in an upcoming release.

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