Automated Builds Failing with custom DockerFile location


I am having an issue with my automated build as they are no longer working when I specify a custom dockerfile.
My dockerfile is DockerFile-PyPi and yesterday (12/7/2019) it worked with this build. However, today (12/8/2019) my builds are no longer working (example). I have not changed anything with the build. Is there something that I am missing?