Phabricator (and several other services) don't get along well with the symlink swapping done by scap3 during the promote / rollback stages.
I wish there was a mode that disabled that and simply rely on git checkout $tag to implement rollback - git checkout leaves .gitignore'd files in place, for example.
When deploying phabricator with scap3 I have to run puppet after each deploy to recreate a bunch of stuff. I guess phabricator's puppet module needs to be fixed instead of scap but it's unfortunate that there isn't a way to keep /srv/deployment/repo as a single repository.