OFS/event.py requires a newer zope.interface version

It imports ObjectEvent from zope.interface.interfaces which was moved there in 3.8

setup.py

@@ -93,7 +93,7 @@ setup(name='Zope2',
       'zope.exceptions',
       'zope.i18n [zcml]',
       'zope.i18nmessageid',
-      'zope.interface',
+      'zope.interface >= 3.8',
       'zope.lifecycleevent',
       'zope.location',
       'zope.pagetemplate >= 4.0.2',