Our product team(s) want to generate product (:GA) builds from 2 (or more!) SCM branches at any given point. I'm not referring to Maintenance updates (:Update) projects, but the :GA project.
Here's the workflow and requirement:
1. Development of GA release happens on "trunk" (in SVN and "master" in git terminology) 2. When we are close to a milestone, for example, a Beta drop, we branch trunk so that only Beta showstoppers (or ship stoppers, whichever you prefer) are checked into this new branch. 3. The "trunk" is open for next milestone changes.
Requirement is to generate builds from both these branches - trunk and beta.
Right now, we have been creating a "home" project  to build code from trunk during the "Beta phase". The official :GA project contains source code from the corresponding "Beta" branch. But this is not being accepted as a solution because:
* GPG keys for home projects and GA project are different * We do not build product ISO from home project  * Package versions diverge between GA and home project
I'm writing here to seek any possible solutions that will help solve the above problems. I have been trying to evaluate if Staging projects could help solve this problem, but I'm unable to visualize or understand a typical workflow using Staging projects.
Any tips or suggestions on how to move forward would be greatly appreciated.
 We could also create :GA:BetaX (where X is the n'th Beta we are working on) to solve the GPG keys problem but I don't think (or know) how to solve the version divergence.
 We don't build ISO because Build Service adds the home project into product and package tracking database. I don't know if this is a problem or not, but when "osc sm <package>" lists a home project, it might cause confusion - something I would like to avoid.