pristine-tar can regenerate a pristine upstream tarball using only a small binary delta file and a revision control checkout of the upstream branch. . The package also includes a pristine-gz command, which can regenerate a pristine .gz file. . The delta file is designed to be checked into revision control along-side the upstream branch, thus allowing Debian packages to be built entirely using sources in revision control, without the need to keep copies of upstream tarballs.