Rational Team Build with Git
One answer
My first reaction would be to say that there is probably no Pre-Build option similar to "Jazz Source control" available, that loads the Git data to disc and creates snapshots and the like. You would have to do that using scripts in the build script. I am not sure about this, but I would also expect information like snapshots and the ability to compare the source code and the like on the build results to be unavailable.