This package uses git-buildpackage (with pristine-tar, without a patch
queue).

Documentation of gbp, git build package, is
at http://honk.sigxcpu.org/projects/git-buildpackage/manual-html/gbp.html

You find that doc also in /usr/share/doc/git-buildpackage/manual-html/gbp.html
after installing the package  git-buildpackage
