Thanks @phubar . The regexp issue is a regression that we already had identified. It will go live asap, I will let you know when its gets to production so you can rollback your change.
Respect to the dockerfile location, your are right, we have changed the way autotests works. More information here https://docs.docker.com/docker-cloud/builds/automated-testing/
The way it works now is based on pull requests. When you open a pull requests agains master, it creates an autotest action for every build rule defined for master. In your case, this is “/resources/docker-cloud/builds/dev-db/” and “/Dockerfile” (maybe you could remove the first build rule). This includes build rules with “autobuild == False” at the moment, although it could make more sense to ignore these build rules for autotests.