Run in different threads

[saswat0]

Can I run separate mvp solver instances in different threads simultaneously? I tried using python's multiprocessing module for this. Every time I keep the number of processes/threads as 1, it works as expected but when I increase the number of threads, I get this error: FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmpp105vrd2/1.tmp'

Here's the code for reference:

from pyvpsolver import VPSolver, MVP

def func(i):
    instance = MVP.from_file('demo.mvp')
    out, solution = VPSolver.script(
        "vpsolver_gurobi.sh", instance, verbose=False, options="Threads=12"
    )
    print(solution)

from multiprocessing import Pool

def run_parallel():
    
    list_ranges = [i for i in range(2)]

    pool = Pool(processes=len(list_ranges))
    pool.map(func, list_ranges)
  
if __name__ == '__main__':
    run_parallel()

MVP file (demo.mvp)

4
5
8 4 50 10 1 1
16 8 50 20 1 1
32 16 100 50 1 1
64 32 128 50 1 1
128 64 130 100 1 1
5
1 1
2 2 25 5
1 1
6 8 40 5
1 1
10 16 40 20
1 1
10 16 120 50
1 1
15 12 90 50