2017-09-20T14:36:56.665+0000 I COMMAND  [conn44] CMD: drop pymongo_test.test_change_stream.TestChangeStream.test_iteration
2017-09-20T14:36:56.665+0000 I STORAGE  [conn44] dropCollection: pymongo_test.test_change_stream.TestChangeStream.test_iteration - renaming to drop-pending collection: pymongo_test.system.drop.1505918216i32t2.test_change_stream.TestChangeStream.test_iteration with drop optime { ts: Timestamp 1505918216000|32, t: 2 }
2017-09-20T14:36:56.691+0000 I REPL     [replication-0] Completing collection drop for pymongo_test.system.drop.1505918216i32t2.test_change_stream.TestChangeStream.test_iteration with drop optime { ts: Timestamp 1505918216000|32, t: 2 } (notification optime: { ts: Timestamp 1505918216000|32, t: 2 })
2017-09-20T14:36:56.701+0000 I COMMAND  [conn44] CMD: drop pymongo_test.test_change_stream.TestChangeStream.test_iteration
2017-09-20T14:36:56.732+0000 F -        [conn44] Invariant failure pin == ErrorCodes::CursorNotFound src/mongo/db/cursor_manager.cpp 178
2017-09-20T14:36:56.732+0000 F -        [conn44] 

***aborting after invariant() failure


2017-09-20T14:36:56.741+0000 F -        [conn44] Got signal: 6 (Aborted).


 mongod(_ZN5mongo13CursorManager29eraseCursorGlobalIfAuthorizedEPNS_16OperationContextEiPKc+0x48) [0x7f7977f88c38]
 mongod(_ZN5mongo23ServiceEntryPointMongod13handleRequestEPNS_16OperationContextERKNS_7MessageE+0x1AB9) [0x7f7977a7bc19]
 mongod(_ZN5mongo19ServiceStateMachine15_processMessageERNS0_11ThreadGuardE+0xF0) [0x7f7977a83670]
 mongod(_ZN5mongo19ServiceStateMachine15_runNextInGuardERNS0_11ThreadGuardE+0x1B5) [0x7f7977a80665]

    def test_iteration(self):
        with self.coll.watch(batch_size=2) as change_stream:
            num_inserted = 10
            self.coll.insert_many([{} for _ in range(num_inserted)])
            self.coll.drop()
            received = 0
            for change in change_stream:
                received += 1