--- a/hgext3rd/evolve/obsdiscovery.py	Wed May 17 09:52:06 2017 +0200
+++ b/hgext3rd/evolve/obsdiscovery.py	Tue May 16 11:37:45 2017 +0200
@@ -416,7 +416,7 @@
 
 _reset = "DELETE FROM obshashrange;"
 
-class _obshashcache(obscache.dualsourcecache, dict):
+class _obshashcache(obscache.dualsourcecache):
 
     _schemaversion = 1
 
@@ -428,6 +428,7 @@
         self._repo = weakref.ref(repo.unfiltered())
         # cache status
         self._ondiskcachekey = None
+        self._data = {}
 
     def clear(self, reset=False):
         self._valid = False
@@ -436,6 +437,7 @@
             if con is not None:
                 con.execute(_reset)
         super(_obshashcache, self).clear(reset=reset)
+        self._data.clear()
         self._new.clear()
         if not reset and '_con' in vars(self):
             del self._con
@@ -448,7 +450,7 @@
         if not getattr(self, '_updating', False):
             assert rangeid[0] <= self._cachekey[0]
 
-        value = super(_obshashcache, self).get(rangeid)
+        value = self._data.get(rangeid)
         if value is None and self._con is not None:
             nrange = (rangeid[0], rangeid[1])
             obshash = self._con.execute(_queryobshash, nrange).fetchone()
@@ -458,7 +460,7 @@
 
     def __setitem__(self, rangeid, obshash):
         self._new.add(rangeid)
-        super(_obshashcache, self).__setitem__(rangeid, obshash)
+        self._data[rangeid] = obshash
 
     def _updatefrom(self, repo, revs, obsmarkers):
         """override this method to update your cache data incrementally
@@ -574,7 +576,7 @@
                     data = (meta[2], meta[1], self._ondiskcachekey[0], self._ondiskcachekey[1])
                     repo.ui.warn(msg)
                     return
-        data = ((rangeid[0], rangeid[1], self[rangeid]) for rangeid in self._new)
+        data = ((rangeid[0], rangeid[1], self.get(rangeid)) for rangeid in self._new)
         con.executemany(_updateobshash, data)
         cachekey = self._fullcachekey
         con.execute(_newmeta, cachekey)