Cloning from git and checking out from SVN/Perforce are two different concepts, and a git clone normally clones the entire repo with history intact, which causes problems with repos with lots of asset history. Does Unity Cloud Build pull a shallow clone of the repo for building when using a git repo, or does it clone the full repo?
Unity Cloud Build fetches a new snapshot every build. In the Enterprise plan we can also cache the source on demand and fetch the delta.
This doesn't really answer my question though. SVN and Perforce checkouts don't include the full history. Git does, which is why it's called cloning rather than checking out. Does the full history count against the repo size limit when using Git or only the size of the state of the working directory (or shallow clone)?
It appears that Unity Cloud Build doesn't support building desktop players or HTML5 yet, so it's not tremendously useful for my purposes, but I will definitely give it a shot once either of those are available. Thanks!