### Bug Description When the control port is in use, the fetch service exits almost immediately with status code 0 and no indication that there is an issue. The correct behaviour (exiting with an error and "bind: address already in use") occurs when the proxy port is in use. This appears to be a repeat-regression of #208 ### To Reproduce Run the following in a Python interactive shell: ```python import socket soc = socket.create_server(("localhost", 13444), reuse_port=True) ``` Then run: ``` fetch-service --control-port=13444 --cert=$HOME/snap/fetch-service/common/craft/fetch-certificate/local-ca.pem --key=$HOME/snap/fetch-service/common/craft/fetch-certificate/local-ca.key.pem --proxy-port=13555 ``` ### Relevant log output ```shell 2025/03/19 15:48:59.946769 INFO : Version 0.6.1-0-g312cf84 2025/03/19 15:48:59.946786 INFO : Loading certificate from /home/lengau/snap/fetch-service/common/craft/fetch-certificate/local-ca.pem 2025/03/19 15:48:59.946846 INFO : Loading key from /home/lengau/snap/fetch-service/common/craft/fetch-certificate/local-ca.key.pem 2025/03/19 15:48:59.946874 INFO : create CA from PEM certificate and key blocks 2025/03/19 15:48:59.947454 INFO : ACL configuration file /etc/fetch/acl.yaml does not exist 2025/03/19 15:48:59.947465 INFO : Inspectors configuration file /etc/fetch/inspectors.yaml does not exist 2025/03/19 15:48:59.947469 INFO : Starting service... 2025/03/19 15:48:59.947653 INFO : Starting the HTTP proxy; listening on :13555 2025/03/19 15:48:59.947689 INFO : Listening on fetchctl socket... 2025/03/19 15:48:59.947896 INFO : control server listening on :13444 2025/03/19 15:48:59.948120 INFO : Server exiting! 2025/03/19 15:48:59.948130 INFO : Stopping service... 2025/03/19 15:48:59.948134 INFO : [session] all sessions finished 2025/03/19 15:48:59.948139 INFO : Shutting down the HTTP proxy... 2025/03/19 15:48:59.948206 INFO : Shutting down fetchctl socket... 2025/03/19 15:48:59.948232 INFO : Shutting down the control API server... ```