Hello, I've stumbled upon a wrinkly edge case (bug?) in zope.component. What I was trying to do is register an AbsoluteURL adapter for lovely.remotetask.processor.ProcessorRequest objects, and since they don't implement a specific interface, I thought I'd use the class itself as the required component. But registering the adapter for "* lovely.remotetask.processor.ProcessorRequest" fails with a strange TypeError (see below). The reason is that the class inherits from zope.publisher.base.BaseRequests which uses __slots__. The minimal reproduction recipe to see the error is this: class Slotted(object): __slots__ = ('__provides__') zope.component.provideAdapter( lambda x: True, (Slotted,), zope.interface.Interface) Which will raise File "/home/wosc/.python-eggs/zope.component-3.7.1-py2.6.egg/zope/component/registry.py", line 419, in _getAdapterRequired elif not ISpecification.providedBy(r): TypeError: 'member_descriptor' object is not callable Why is this? Can this be made to work? How would I go about investigating that? Thanks, Wolfgang