'group argument must be None for now' in parallel mode for python 3.8

[Yeqzids]

I am getting the following error when trying to run the example. I am on python=3.8 and zogyp=1.6.3.

Parallell version, using 18 cores
Traceback (most recent call last):
  File "[..]/anaconda3/bin/ZOGY", line 33, in <module>
    sys.exit(load_entry_point('zogyp==1.6.3', 'console_scripts', 'ZOGY')())
  File "[..]/anaconda3/lib/python3.8/site-packages/zogyp-1.6.3-py3.8.egg/zogyp/ZOGY.py", line 153, in main
    run_ZOGY(sci_T, ref_T, clean_ref=cleanref, clean_sci=cleansci,
  File "[..]/anaconda3/lib/python3.8/site-packages/zogyp-1.6.3-py3.8.egg/zogyp/zip.py", line 715, in run_ZOGY
    p = NoDaemonProcessPool(processes = ncores)
  File "[..]/anaconda3/lib/python3.8/multiprocessing/pool.py", line 212, in __init__
    self._repopulate_pool()
  File "[..]/anaconda3/lib/python3.8/multiprocessing/pool.py", line 303, in _repopulate_pool
    return self._repopulate_pool_static(self._ctx, self.Process,
  File "[..]/anaconda3/lib/python3.8/multiprocessing/pool.py", line 319, in _repopulate_pool_static
    w = Process(ctx, target=worker,
  File "[..]/anaconda3/lib/python3.8/multiprocessing/process.py", line 82, in __init__
    assert group is None, 'group argument must be None for now'

After some research, I think this relates to https://stackoverflow.com/questions/52948447/error-group-argument-must-be-none-for-now-in-multiprocessing-pool. I can't quite follow the fix mentioned in that thread (nipy/nipype#2754), but downgrading to python=3.5 resolves the problem.

[EA4096]

Resolved this problem in Python 3.5 rewriting NoDaemonProcess and NoDaemonProcessPool classes as follows:

class NoDaemonProcess(multiprocessing.Process):
    # make 'daemon' attribute always return False
    @property
    def daemon(self):
        return False

    @daemon.setter
    def daemon(self, val):
        pass

class NoDaemonProcessPool(multiprocessing.pool.Pool):

    def Process(self, *args, **kwds):
        proc = super(NoDaemonProcessPool, self).Process(*args, **kwds)
        proc.__class__ = NoDaemonProcess

        return proc