Distributed build systems

Which tools for distributed builds are currently in use in popular Linux distros, like Ubuntu, Debian, RedHat, etc.? For example, we have a huge amount of packages with dependencies and try to compile all of them for the new release of the distro. It takes a lot of time to build them one by one. I have heard about distcc, but it shares one project compilation between the servers for distributed parallel building. Is there any tool which analyzes dependencies between the packages (creates a graph, for example) and creates a schedule for building with package-level parallelism? For example, we have packages p1, p2, p3, p4, and two servers. One server builds p1, another p2 at the same time if they are not dependent on each other. I need examples of the projects which are being used in production.