error when multiprocessing with memory_logger on Windows

[fneum]

 File "C:\Users\travis\build\PyPSA\pypsa-eur\.snakemake\shadow\tmpi4zbpqvn\.snakemake\scripts\tmp1jwceb1d.solve_network.py", line 394, in <module>

    with memory_logger(filename=getattr(snakemake.log, 'memory', None), interval=30.) as mem:

  File "C:\miniconda\envs\pypsa-eur\lib\site-packages\vresutils\benchmark.py", line 161, in __enter__

    self.p.start()

  File "C:\miniconda\envs\pypsa-eur\lib\multiprocessing\process.py", line 112, in start

    self._popen = self._Popen(self)

  File "C:\miniconda\envs\pypsa-eur\lib\multiprocessing\context.py", line 223, in _Popen

    return _default_context.get_context().Process._Popen(process_obj)

  File "C:\miniconda\envs\pypsa-eur\lib\multiprocessing\context.py", line 322, in _Popen

    return Popen(process_obj)

  File "C:\miniconda\envs\pypsa-eur\lib\multiprocessing\popen_spawn_win32.py", line 89, in __init__

    reduction.dump(process_obj, to_child)

  File "C:\miniconda\envs\pypsa-eur\lib\multiprocessing\reduction.py", line 60, in dump

    ForkingPickler(file, protocol).dump(obj)

TypeError: cannot serialize '_io.TextIOWrapper' object

related: PyPSA/pypsa-eur#42

[coroa]

Somewhat related, but not really.