forgot to add class name as requested by Jim

src/ZODB/ConflictResolution.py

@@ -239,6 +239,7 @@ _unresolvable = {}
 def tryToResolveConflict(self, oid, committedSerial, oldSerial, newpickle,
                          committedData=b''):
     # class_tuple, old, committed, newstate = ('',''), 0, 0, 0
+    klass = 'n/a'
     try:
         prfactory = PersistentReferenceFactory()
         newpickle = self._crs_untransform_record_data(newpickle)
@@ -295,15 +296,17 @@ def tryToResolveConflict(self, oid, committedSerial, oldSerial, newpickle,
         pickler.dump(resolved)
         return self._crs_transform_record_data(file.getvalue())
     except (ConflictError, BadClassName) as e:
-        logger.debug("Conflict resolution failed with %s: %s" % (
-            e.__class__.__name__, str(e)))
+        logger.debug(
+            "Conflict resolution on %s failed with %s: %s",
+            klass, e.__class__.__name__, str(e))
     except:
         # If anything else went wrong, catch it here and avoid passing an
         # arbitrary exception back to the client.  The error here will mask
         # the original ConflictError.  A client can recover from a
         # ConflictError, but not necessarily from other errors.  But log
         # the error so that any problems can be fixed.
-        logger.exception("Unexpected error")
+        logger.exception(
+            "Unexpected error while trying to resolve conflict on %s", klass)
 
     raise ConflictError(oid=oid, serials=(committedSerial, oldSerial),
                         data=newpickle)

src/ZODB/tests/testconflictresolution.py

@@ -355,11 +355,11 @@ Let's see what went into the log:
 
     >>> msg = handler.records[0]
     >>> six.print_(msg.name, msg.levelname, msg.getMessage())
-    ZODB.ConflictResolution ERROR Unexpected error
+    ZODB.ConflictResolution ERROR Unexpected error while trying to resolve conflict on <class 'ZODB.tests.testconflictresolution.FailHard'>
 
     >>> msg = handler.records[1]
     >>> six.print_(msg.name, msg.levelname, msg.getMessage())
-    ZODB.ConflictResolution DEBUG Conflict resolution failed with ConflictError: database conflict error
+    ZODB.ConflictResolution DEBUG Conflict resolution on <class 'ZODB.tests.testconflictresolution.Unresolvable'> failed with ConflictError: database conflict error
 
 Cleanup:
 
@@ -381,4 +381,3 @@ def test_suite():
             setUp=setUp, tearDown=tearDown,
             checker=ZODB.tests.util.checker),
         ])
-