BrokenPipeError: [Errno 32] Broken pipe

[Videet Nimsarkar]

Preparing directory '/'
Using model PreResNet110
Loading dataset CIFAR10 from '/'
Files already downloaded and verified
Files already downloaded and verified
Preparing model
SGD training
Preparing directory '/'
Using model PreResNet110
Loading dataset CIFAR10 from '/'
Files already downloaded and verified
Files already downloaded and verified
Preparing model
SGD training
Traceback (most recent call last):
File "", line 1, in
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 105, in spawn_main
exitcode = _main(fd)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 114, in _main
prepare(preparation_data)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 225, in prepare
_fixup_main_from_path(data['init_main_from_path'])
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
run_name="mp_main")
File "C:\Users\Videet\Anaconda3\lib\runpy.py", line 263, in run_path
pkg_name=pkg_name, script_name=fname)
File "C:\Users\Videet\Anaconda3\lib\runpy.py", line 96, in _run_module_code
mod_name, mod_spec, pkg_name, script_name)
File "C:\Users\Videet\Anaconda3\lib\runpy.py", line 85, in _run_code
Traceback (most recent call last):
exec(code, run_globals)
File "train.py", line 148, in
File "C:\Users\Videet\SWA\swa-master\train.py", line 148, in
train_res = utils.train_epoch(loaders['train'], model, criterion, optimizer)
train_res = utils.train_epoch(loaders['train'], model, criterion, optimizer)
File "C:\Users\Videet\SWA\swa-master\utils.py", line 26, in train_epoch
File "C:\Users\Videet\SWA\swa-master\utils.py", line 26, in train_epoch
for i, (input, target) in enumerate(loader):
for i, (input, target) in enumerate(loader):
File "C:\Users\Videet\Anaconda3\lib\site-packages\torch\utils\data\dataloader.py", line 451, in iter
File "C:\Users\Videet\Anaconda3\lib\site-packages\torch\utils\data\dataloader.py", line 451, in iter
return _DataLoaderIter(self)
File "C:\Users\Videet\Anaconda3\lib\site-packages\torch\utils\data\dataloader.py", line 239, in init
return _DataLoaderIter(self)
w.start()
File "C:\Users\Videet\Anaconda3\lib\site-packages\torch\utils\data\dataloader.py", line 239, in init
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\process.py", line 105, in start
w.start()
self._popen = self._Popen(self)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\process.py", line 105, in start
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\context.py", line 223, in _Popen
self._popen = self._Popen(self)
return _default_context.get_context().Process._Popen(process_obj)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\context.py", line 223, in _Popen
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\context.py", line 322, in _Popen
return _default_context.get_context().Process._Popen(process_obj)
return Popen(process_obj)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\context.py", line 322, in _Popen
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\popen_spawn_win32.py", line 65, in init
return Popen(process_obj)
reduction.dump(process_obj, to_child)
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\reduction.py", line 60, in dump
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\popen_spawn_win32.py", line 33, in init
ForkingPickler(file, protocol).dump(obj)
prep_data = spawn.get_preparation_data(process_obj._name)
BrokenPipeError: [Errno 32] Broken pipe
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 143, in get_preparation_data
_check_not_importing_main()
File "C:\Users\Videet\Anaconda3\lib\multiprocessing\spawn.py", line 136, in _check_not_importing_main
is not going to be frozen to produce an executable.''')
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.

    This probably means that you are not using fork to start your
    child processes and you have forgotten to use the proper idiom
    in the main module:

        if __name__ == '__main__':
            freeze_support()
            ...

    The "freeze_support()" line can be omitted if the program
    is not going to be frozen to produce an executable.

[Pavel Izmailov]

It looks like your error is not related to our SWA code. It happens inside a dataloader. I think you should try to make a minimal reproducible example of this error and create an issue in the PyTorch repo.

[付达]

I came across the BrokenPipeError, when I tried to run on cpu. I change num_workers to 0, it runs.