[pypy-issue] Issue #2421: multiprocessing.Pool under PyPy3.5 fails (pypy/pypy)

[Daniil Yarancev]

New issue 2421: multiprocessing.Pool under PyPy3.5 fails
https://bitbucket.org/pypy/pypy/issues/2421/multiprocessingpool-under-pypy35-fails

Daniil Yarancev:

Trying this simple example with PyPy3.5:

```
#!python

from multiprocessing import Pool

def f(x):
    return x*x

if __name__ == '__main__':
    p = Pool(5)
    print(p.map(f, [1, 2, 3]))
```
CPython 3.5.2 works as expected: [1, 4, 9]
PyPy3.5 fails with error:
https://paste.pound-python.org/show/IoKfW0weIXMImtbKYvUO/