Hi Ken, 

Thanks for your comment.

Unfortunately at the time I can not upgrade to 3.8 to run this test. My whole system depends on 3.7 and some peculiarities of 3.8 need to be dealt with.

It would be great if someone with OSX and 3.8 could test this out, otherwise I will dig into this later creating a new environment.

> On 11 Nov 2020, at 18:12, Ken Jin <report@bugs.python.org> wrote:
> 
> 
> Ken Jin <kenjin4096@gmail.com> added the comment:
> 
> Danil, thanks for finding the cause behind this. Could you check if the new behavior in Python 3.8 and higher has the same problem on your machine (without your fix)? multiprocessing on MacOS started using spawn in 3.8, and I was wondering if it that fixed it.
> 
> What's new entry for 3.8 : 
> https://docs.python.org/3/whatsnew/3.8.html#multiprocessing
> 
> The bug tracked:
> https://bugs.python.org/issue33725
> 
> The PR for that
> https://github.com/python/cpython/pull/13603/files
> 
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> <https://bugs.python.org/issue42245>
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