free-threaded-optuna-bruteforce-sampler-error.py

import optuna
from concurrent.futures import ThreadPoolExecutor

optuna.logging.set_verbosity(optuna.logging.WARNING)


def test_free_threaded():
    study = optuna.create_study(sampler=optuna.samplers.BruteForceSampler())

    def objective(trial):
        s = 0
        for i in range(10):
            s += trial.suggest_int(f"x{i}", 0, 10)
        return s

    study.optimize(
        objective,
        n_trials=50,
        n_jobs=5,
    )


if __name__ == "__main__":
    with ThreadPoolExecutor() as executor:
        for _ in range(5):
            executor.submit(test_free_threaded)