How to use set_progress with long_callback with multiprocessing?

I have an app that has a long_callback and within that long callback I use multiprocessing to speed it up. I tried to pass in the set_progress to the multiprocessing function and I get an error.

Can’t pickle local object ‘_make_job_fn..job_fn.._set_progress’

Is there a way for multiprocessing functions to report on progress?