Projects can now have a branch key in their plist which will cause darwinbuild to use subversion to checkout/update the source instead of downloading a tarball. You can see an example of this at the SmartCard Services project. Darwinbuild will assume -nosource when a project is subversion-based. The working copy is in the same place as usual, at BuildRoot/SourceCache/project/project-version/. This should allow developers to take advantage of the chroot and automatic root fetching of darwinbuild, while being able to make changes between builds and commit directly from the SourceCache.