At UDS Karmic, we discussed providing daily builds of pristine upstream projects.
Specifically, I implemented this for the key virtualization packages, per https://blueprints.launchpad.net/ubuntu/+spec/server-karmic-pristine-daily-virt-builds:
I have constructed some automation that builds Debian/Ubuntu binaries for amd64, i386, and lpia platforms directly from your master git repositories every day at 11:00 UTC, and publishes them in a special, opt-in repository. These daily builds also drop any specific patches we may be carrying, in order to minimize the delta between the binaries built and your upstream sources.
Additionally, this tool also has the ability to expose build breakages, and it has revealed several during the last few weeks as I have been developing it.
If anyone has suggestions as to the utility of this resource, I would appreciate constructive feedback.