No meu caso ocorreu:
Traceback (most recent call last): File "C:\Temp\publish-test.py", line 4, in mqttc.connect("mqtt.eclipse.org", 1883) File "C:\Users\Alexei\AppData\Local\Programs\Python\Python310\lib\site-packages\paho\mqtt\client.py", line 914, in connect return self.reconnect() File "C:\Users\Alexei\AppData\Local\Programs\Python\Python310\lib\site-packages\paho\mqtt\client.py", line 1044, in reconnect sock = self.createsocket_connection() File "C:\Users\Alexei\AppData\Local\Programs\Python\Python310\lib\site-packages\paho\mqtt\client.py", line 3685, in createsocket_connection return socket.create_connection(addr, timeout=self.connecttimeout, source_address=source) File "C:\Users\Alexei\AppData\Local\Programs\Python\Python310\lib\socket.py", line 824, in create_connection for res in getaddrinfo(host, port, 0, SOCK_STREAM): File "C:\Users\Alexei\AppData\Local\Programs\Python\Python310\lib\socket.py", line 955, in getaddrinfo for res in _socket.getaddrinfo(host, port, family, type, proto, flags): socket.gaierror: [Errno 11001] getaddrinfo failed