多进程执行仿真命令时，每个子进程加载Shell文件后程序卡住的问题排查

我正在编写一段代码，目的是收集仿真命令并通过多进程执行，每个子进程在运行仿真命令前会先加载一个shell文件。我在另一个函数中把这些命令收集到字典里，供下面的函数使用：

def source_shell_script(self, script_path: str) -> dict:
    """
    Sources a shell script and updates the environment for each subprocess.
    """
    if not os.path.exists(script_path):
        raise FileNotFoundError(f"Script not found: {script_path}")
    
    # source the script and output environment variables
    command = f"bash -c 'source {script_path} && env'"
    
    try:
        # run the command and capture the output
        result = subprocess.run(command, shell=True, stdout=subprocess.PIPE, text=True, check=True)
        # parse the environment variables from the command output
        env_vars = dict(
            line.split("=", 1) for line in result.stdout.splitlines() if "=" in line
        )
        return env_vars
    except subprocess.CalledProcessError as e:
        raise RuntimeError(f"Failed to source script: {script_path}. Error: {e}")

def run_cmd(self, cmd_px: tuple) -> None:
    cmd, px_src_path = cmd_px
    try:
        # get environment variables
        env_vars = self.source_shell_script(px_src_path)
        print(f"Executing command: {cmd}")
        result = subprocess.run(cmd, shell=True, env=env_vars, stdout=subprocess.PIPE, stderr=subprocess.PIPE, text=True)
        print(f"Output: {result.stdout}")
        if result.returncode != 0:
            print(f"Error: {result.stderr}")
    except Exception as e:
        print(f"Failed to execute command: {cmd}. Error: {e}")

def exec_sim(self) -> None:
    """
    Execute all simulations in parallel using multiprocessing.
    """
    # create a list of (command, px_src_path) tuples for each pixel configuration
    run_queue = [(cmd, self.sim_dict[px_key]["px_src_path"]) 
                for px_key in self.sim_dict 
                for cmd in self.sim_dict[px_key]["px_ddsim_cmds"]]
    
    num_workers = os.cpu_count()  # number of processes
    with multiprocessing.Pool(num_workers) as pool:
        pool.map(self.run_cmd, run_queue)

if __name__ == "__main__":
    # initialize program
    eic_object = HandleEIC()
    eic_object.init_path_var()
    pixel_sizes = eic_object.setup_json()
    eic_object.pixel_sizes = pixel_sizes  
    os.chmod(eic_object.execution_path, 0o777)
    
    eic_object.setup_sim()
    print("Simulation dictionary:", eic_object.sim_dict)
    
    eic_object.exec_sim()

    # create backup for simulation
    eic_object.mk_sim_backup()

但程序并没有正常运行，而是卡住了，控制台只打印出了命令：

控制台输出：

Simulation dictionary: {'2.0_0.1': {'px_epic_path': '/data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic', 'px_compact_path': '/data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic/install/share/epic/compact', 'px_ip6_path': '/data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic/install/share/epic/epic_ip6_extended.xml', 'px_src_path': '/data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic/install/bin/thisepic.sh', 'px_out_path': '/data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px', 'px_ddsim_cmds': ['ddsim --inputFiles /data/user/Analysis_epic_new/simulations/genEvents/results/beamEffectsElectrons_20.hepmc --outputFile /data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/output_20edm4hep.root --compactFile /data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic/install/share/epic/epic_ip6_extended.xml -N 5']}, '0.1_0.1': {'px_epic_path': '/data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic', 'px_compact_path': '/data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic/install/share/epic/compact', 'px_ip6_path': '/data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic/install/share/epic/epic_ip6_extended.xml', 'px_src_path': '/data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic/install/bin/thisepic.sh', 'px_out_path': '/data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px', 'px_ddsim_cmds': ['ddsim --inputFiles /data/user/Analysis_epic_new/simulations/genEvents/results/beamEffectsElectrons_20.hepmc --outputFile /data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/output_20edm4hep.root --compactFile /data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic/install/share/epic/epic_ip6_extended.xml -N 5']}}
Executing command: ddsim --inputFiles /data/user/Analysis_epic_new/simulations/genEvents/results/beamEffectsElectrons_20.hepmc --outputFile /data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/output_20edm4hep.root --compactFile /data/user/Analysis_epic_new/simulations/simEvents/0.1x0.1px/epic/install/share/epic/epic_ip6_extended.xml -N 5
Executing command: ddsim --inputFiles /data/user/Analysis_epic_new/simulations/genEvents/results/beamEffectsElectrons_20.hepmc --outputFile /data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/output_20edm4hep.root --compactFile /data/user/Analysis_epic_new/simulations/simEvents/2.0x0.1px/epic/install/share/epic/epic_ip6_extended.xml -N 5

为什么我的代码没有按预期运行？我哪里做错了？

备注：内容来源于stack exchange，提问作者Niandra Lades