Can't run MATLAB engine processes in parallel on Linux

[alexhroom]

see the following example, first with threads:

import matlab.engine
from concurrent.futures import ThreadPoolExecutor

def matlab_func(i):
    eng = matlab.engine.start_matlab()
    return eng.sqrt(i)

with ThreadPoolExecutor() as executor:
    future = executor.submit(matlab_func, 4.0)
    print(future.result())

vs the same with Processes:

import matlab.engine
from concurrent.futures import ProcessPoolExecutor

def matlab_func(i):
    eng = matlab.engine.start_matlab()
    return eng.sqrt(i)

with ProcessPoolExecutor() as executor:
    future = executor.submit(matlab_func, 4.0)
    print(future.result())

I find that the thread example works, but the process example runs forever.

This is with matlabengine version 24.2.2, MATLAB R2024b Update 3 on Linux.