Remove --log-syslog from the supervisor gunicorn command  line
Remove --log-syslog from the supervisor gunicorn command  line

Supervisor is already redirecting stdout to syslog with the stdout_logfile=syslog line.
Writing to syslog twice causes an "OSError: [Errno 9] Bad file descriptor" error and a large stack trace in syslog for every 200 response.
caktus/tequila-django