Thanks, I get it now, I hadn't seen that the pickling of the workers was
Processes pickling.
Yeah, I was not doing this anywhere else, it seems like slipped through
once. But it called my attention that it used to work and now it doesn't.

On Tue, Jul 3, 2018 at 4:38 PM, Antoine Pitrou <report@bugs.python.org>
wrote:

>
> Antoine Pitrou <pitrou@free.fr> added the comment:
>
> It could be many different things.  The bottom line here, though, is that
> the Process class is not designed to be picklable (how would it work?),
> which is probably why you're seeing this.
>
> ----------
> nosy: +pitrou
>
> _______________________________________
> Python tracker <report@bugs.python.org>
> <https://bugs.python.org/issue34034>
> _______________________________________
>