Can't pickle local object 'DataLoader.__init__.<locals>.<lambda>'

@albanD I have reproduced the error here : https://colab.research.google.com/drive/10Zxe40Tl14fWAaCAYg1fgQA13hHIiBo_?usp=sharing

The error is :

AttributeError                            Traceback (most recent call last)
<ipython-input-6-adca9abddcf0> in <module>()
    168 if __name__ == '__main__':
    169     t1 = time.time()
--> 170     main()
    171     print("Time taken :", time.time() - t1)

5 frames
<ipython-input-6-adca9abddcf0> in main(ways, shots, meta_lr, fast_lr, meta_batch_size, adaptation_steps, num_iterations, cuda, seed)
    126         args = [maml, tasksets]
    127         with Pool(4) as pool:
--> 128           values = pool.map(partial(ParallelTasks, args), list(range(meta_batch_size)))
    129 
    130         #for i in range(values):

/usr/lib/python3.6/multiprocessing/pool.py in map(self, func, iterable, chunksize)
    264         in a list that is returned.
    265         '''
--> 266         return self._map_async(func, iterable, mapstar, chunksize).get()
    267 
    268     def starmap(self, func, iterable, chunksize=None):

/usr/lib/python3.6/multiprocessing/pool.py in get(self, timeout)
    642             return self._value
    643         else:
--> 644             raise self._value
    645 
    646     def _set(self, i, obj):

/usr/lib/python3.6/multiprocessing/pool.py in _handle_tasks(taskqueue, put, outqueue, pool, cache)
    422                         break
    423                     try:
--> 424                         put(task)
    425                     except Exception as e:
    426                         job, idx = task[:2]

/usr/lib/python3.6/multiprocessing/connection.py in send(self, obj)
    204         self._check_closed()
    205         self._check_writable()
--> 206         self._send_bytes(_ForkingPickler.dumps(obj))
    207 
    208     def recv_bytes(self, maxlength=None):

/usr/lib/python3.6/multiprocessing/reduction.py in dumps(cls, obj, protocol)
     49     def dumps(cls, obj, protocol=None):
     50         buf = io.BytesIO()
---> 51         cls(buf, protocol).dump(obj)
     52         return buf.getbuffer()
     53 

AttributeError: Can't pickle local object 'omniglot_tasksets.<locals>.<lambda>'