Before updates are propagated in NUR, we check for evaluation errors.
Until now we checked for updates on a daily base using a travis cron job.
Now there is an update service to trigger updates more frequently: https://github.com/nix-community/NUR#update-nurs-lock-file-after-updating-your-repository
Also checkout the source code here: GitHub - nix-community/nur-update: Service to trigger updates of the NUR repository [maintainer=@Mic92]