I get the following message daily:

Anacron job 'cron.daily'
/etc/cron.daily/logrotate:
error: uwsgi-emperor:1 duplicate log entry for /var/log/uwsgi/emperor.log

The issue seems to be that UWSGI and UWSGI Emperor have conflicting configurations: in /etc/logrotate.d/ ...

/etc/logrotate.d/uwsgi

"/var/log/uwsgi/*.log" "/var/log/uwsgi/app/*.log" {
  copytruncate
  daily
  rotate 5
  compress
  delaycompress
  missingok
  notifempty
}

/etc/logrotate.d/uwsgi-emperor

"/var/log/uwsgi/emperor.log" {
  copytruncate
  daily
  rotate 5
  compress
  delaycompress
  missingok
  notifempty
}

...here you can see "emperor.log" matches both criteria.

I assume this issue is inherited from Debian configuration, but I'm not sure which package to report it under. Any advice appreciated.