If the --sender option gets an invalid email address, such as "root@example.com(crondaemon)", then there is no parseable output. This leads to unexpected errors in Enigmail:
gpg --batch --no-tty --status-fd 2 --sender "root@example.com(crondaemon)" --decrypt
--> gpg: "root@example.com(crondaemon)" is not a proper mail address