You have the ability to inform foreman a system is built with URL 'https://foreman/unattended/built'. Similar functionality would be nice to inform foreman that a build has failed, perhaps with a URL like 'https://foreman/unattended/failed'

Even better would be if there could be a way to pass a message/string to show in foreman to help identify where the build failed. Like 'https://foreman/unattended/failed?error=error message here' maybe?