________ TestsProcessPoolForkserverExecutor.test_memory_leak_protection ________
loky.process_executor._RemoteTraceback: 
"""
Traceback (most recent call last):
  File "/home/travis/build/tomMoral/loky/loky/process_executor.py", line 422, in _process_worker
    r = call_item.fn(*call_item.args, **call_item.kwargs)
  File "/home/travis/build/tomMoral/loky/tests/_test_process_executor.py", line 818, in _leak_some_memory
    leaked_size = sum(len(buffer) for buffer in os._loky_leak)
  File "/home/travis/build/tomMoral/loky/tests/_test_process_executor.py", line 818, in <genexpr>
    leaked_size = sum(len(buffer) for buffer in os._loky_leak)
KeyError: 'sum'
"""
The above exception was the direct cause of the following exception:
self = <tests.test_process_executor_forkserver.TestsProcessPoolForkserverExecutor object at 0x7fa0dc462860>
    def test_memory_leak_protection(self):
        self.executor.shutdown(wait=True)
    
        executor = self.executor_type(1, context=self.context)
    
        def _leak_some_memory(size=int(1e6), delay=0.001):
            """function that leaks some memory """
            from loky import process_executor
            process_executor._MEMORY_LEAK_CHECK_DELAY = 0.1
            if getattr(os, '_loky_leak', None) is None:
                os._loky_leak = []
    
            os._loky_leak.append(b"\x00" * size)
    
            # Leave enough time for the memory leak detector to kick-in:
            # by default the process does not check its memory usage
            # more than once per second.
            time.sleep(delay)
    
            leaked_size = sum(len(buffer) for buffer in os._loky_leak)
            return os.getpid(), leaked_size
    
        with pytest.warns(UserWarning, match='memory leak'):
            futures = []
            for i in range(300):
                # Total run time should be 3s which is way over the 1s cooldown
                # period between two consecutive memory checks in the worker.
                futures.append(executor.submit(_leak_some_memory))
    
            executor.shutdown(wait=True)
>           results = [f.result() for f in futures]
_leak_some_memory = <function ExecutorTest.test_memory_leak_protection.<locals>._leak_some_memory at 0x7fa0dd5007b8>
executor   = <loky.process_executor.ProcessPoolExecutor object at 0x7fa0dc4624a8>
futures    = [<Future at 0x7fa0dc452d68 state=finished raised KeyError>, <Future at 0x7fa0dc452278 state=finished raised KeyError>,...ture at 0x7fa0dc449cc0 state=finished raised KeyError>, <Future at 0x7fa0dc449f98 state=finished raised KeyError>, ...]
i          = 299
self       = <tests.test_process_executor_forkserver.TestsProcessPoolForkserverExecutor object at 0x7fa0dc462860>
tests/_test_process_executor.py:829: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
tests/_test_process_executor.py:829: in <listcomp>
    results = [f.result() for f in futures]
/opt/python/3.4.6/lib/python3.4/concurrent/futures/_base.py:395: in result
    return self.__get_result()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <Future at 0x7fa0dc452d68 state=finished raised KeyError>
    def __get_result(self):
        if self._exception:
>           raise self._exception
E           KeyError: 'sum'
self       = <Future at 0x7fa0dc452d68 state=finished raised KeyError>
/opt/python/3.4.6/lib/python3.4/concurrent/futures/_base.py:354: KeyError
---------------------------- Captured stderr setup -----------------------------