Hacky script to try to repair your database after problems with interfaces and the relation catalog

lala.py

# It was hard to figure out, it might now be appropriate to use in your case.
# If you are not feeling comfortable to work on your database like this,
# don't run this gist.

from BTrees.OIBTree import OITreeSet
from ZODB.broken import Broken
from zc.relation.interfaces import ICatalog
from zope.component import getUtility
import transaction


cat = getUtility(ICatalog)

def is_broken(obj):
    if not obj:
        return False
    try:
        iterator = iter(obj)
    except TypeError:
        iterator = [obj]
    for item in iterator:
        try:
            if issubclass(item, Broken):
                return True
        except TypeError:
            continue
    return False

for key, value in cat._reltoken_name_TO_objtokenset.items():
    if not is_broken(value):
        # This is here because I was stupid once 6 lines later. Sorry.
        if isinstance(value, list):
            cat._reltoken_name_TO_objtokenset[key] = OITreeSet(value)
        continue
    if not isinstance(value, OITreeSet):
        continue
    cat._reltoken_name_TO_objtokenset[key] = OITreeSet(filter(lambda x:not is_broken(x), value))

for name in ('from_interfaces_flattened', 'to_interfaces_flattened'):
    for key, (ignore, intids) in cat._name_TO_mapping[name].items():
        if is_broken(key):
            cat._name_TO_mapping.pop(key)
        for intid in intids:
            # I am not sure if it is an error that this can occur. Sorry.
            if (intid, name) not in cat._reltoken_name_TO_objtokenset:
                cat._reltoken_name_TO_objtokenset[(intid, name)] = OITreeSet([key])
            if key not in cat._reltoken_name_TO_objtokenset[(intid, name)]:
                cat._reltoken_name_TO_objtokenset[(intid, name)].add(key)

if not transaction.get()._resources[0]._registered_objects:
    print "Too bad, nothing changed"
# transaction.commit()