Crash in mnist example with num_workers > 0

I'm getting a crash in the mnist example at the end of the 1st epoch when I run with any num_workers > 0 I'm running the python code in PyCharm debugger on a Ubuntu 16.04 system with PyTorch 1.0 with CUDA enabled.

raceback (most recent call last): File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1741, in Traceback (most recent call last): File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1741, in main() File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1735, in main main() File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1735, in main globals = debugger.run(setup['file'], None, None, is_module) File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1135, in run globals = debugger.run(setup['file'], None, None, is_module) File "/snap/pycharm-community/108/helpers/pydev/pydevd.py", line 1135, in run pydev_imports.execfile(file, globals, locals) # execute the script File "/snap/pycharm-community/108/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile pydev_imports.execfile(file, globals, locals) # execute the script File "/snap/pycharm-community/108/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile exec(compile(contents+"\n", file, 'exec'), glob, loc)exec(compile(contents+"\n", file, 'exec'), glob, loc)

File "/home/ankur/dev/benchmark/mnist_main.py", line 119, in File "/home/ankur/dev/benchmark/mnist_main.py", line 119, in main()main()

File "/home/ankur/dev/benchmark/mnist_main.py", line 112, in main File "/home/ankur/dev/benchmark/mnist_main.py", line 112, in main test(args, model, device, test_loader)test(args, model, device, test_loader)

File "/home/ankur/dev/benchmark/mnist_main.py", line 49, in test File "/home/ankur/dev/benchmark/mnist_main.py", line 49, in test for data, target in test_loader:for data, target in test_loader:

File "/home/ankur/miniconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 819, in iter File "/home/ankur/miniconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 631, in next idx, batch = self._get_batch() File "/home/ankur/miniconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 601, in _get_batch return _DataLoaderIter(self) File "/home/ankur/miniconda3/lib/python3.7/site-packages/torch/utils/data/dataloader.py", line 560, in init return self.data_queue.get(timeout=MP_STATUS_CHECK_INTERVAL) File "/home/ankur/miniconda3/lib/python3.7/queue.py", line 179, in get w.start() File "/home/ankur/miniconda3/lib/python3.7/multiprocessing/process.py", line 112, in start self.not_empty.wait(remaining) File "/home/ankur/miniconda3/lib/python3.7/threading.py", line 300, in wait self._popen = self._Popen(self) File "/home/ankur/miniconda3/lib/python3.7/multiprocessing/context.py", line 223, in _Popen gotit = waiter.acquire(True, timeout) return _default_context.get_context().Process._Popen(process_obj) File "/home/ankur/miniconda3/lib/python3.7/multiprocessing/context.py", line 277, in _Popen KeyboardInterrupt return Popen(process_obj) File "/home/ankur/miniconda3/lib/python3.7/multiprocessing/popen_fork.py", line 20, in init self._launch(process_obj) File "/home/ankur/miniconda3/lib/python3.7/multiprocessing/popen_fork.py", line 70, in _launch self.pid = os.fork() File "/snap/pycharm-community/108/helpers/pydev/_pydev_bundle/pydev_monkey.py", line 496, in new_fork