Handle any unhandledRejections or uncaughtExceptions that occur outside request handlers. * If email-address is set, errors will be sent to the supplied address. * If build-id is set, it will be added to the log.

Errors are also written to the rotated file logs/error.log and stderr.

You can get a build-id using git rev-parse HEAD | cut -b -8 > build-id.txt and including it with (rc/inline).