How to debug a freezing python script that seems having no bug at all?

Question

I'm trying this answer approach, yet blender --python blender_server.py opens blender as blank (grey window, not even splash screen).

Pasting the script with Alt+P afterwords blender --factory-startup --verbose -1 freezes blender completely. Only killall blender stops blender. No errors at all.

• Linux
• Blender 3.10 or 2.93

blender_server.py:

# Script to run from blender:
#   blender --python blender_server.py
PORT = 8081
HOST = "localhost"
PATH_MAX = 4096
def execfile(filepath):
    import os
    global_namespace = {
        "file": filepath,
        "name": "main",
    }
    with open(filepath, 'rb') as file:
        exec(compile(file.read(), filepath, 'exec'), global_namespace)
def main():
    import socket
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind((HOST, PORT))
serversocket.listen(1)

print("Listening on %s:%s" % (HOST, PORT))
while True:
    connection, address = serversocket.accept()
    buf = connection.recv(PATH_MAX)

    for filepath in buf.split(b'\x00'):
        if filepath:
            print("Executing:", filepath)
            try:
                execfile(filepath)
            except:
                import traceback
                traceback.print_exc()



if name == "main":
    main()

Answer 1

You have two joint components to a problem here. One is that you are not passing the -b flag first, so a window does open. The other is that the script has a loop in it that will hold blender indefinitely, so of course the window never responds.