To convert an svn repository containing only "/debian" to something compatible with git-buildpackage, you need to some work. Luckily zack already figured out how.

#

package=bibutils
version=3.40
mkdir $package
cd $package
git-svn init --stdlayout --no-metadata svn://svn.debian.org/debian-science/$package
git-svn fetch
# drop upstream branch from svn
git-branch -d -r upstream

# create a new upstream branch based on recipe from  zack
# 
git-symbolic-ref HEAD refs/heads/upstream
git rm --cached -r .
git commit --allow-empty -m 'initial upstream branch'
git checkout -f master
git merge upstream
git-import-orig --pristine-tar --no-dch ../tarballs/${package}_${version}.orig.tar.gz

If you forget to use --authors-file=file then you can fix up your mistakes later with something like the following. Note that after some has cloned your repo, this makes life difficult for them.

#!/bin/sh

project=vrr
name="David Bremner"
email="bremner@unb.ca"

git clone alioth.debian.org:/git/debian-science/packages/$project $project.new
cd $project.new
git branch upstream origin/upstream
git branch pristine-tar origin/pristine-tar
git-filter-branch --env-filter "export GIT_AUTHOR_EMAIL='bremner@unb.ca' GIT_AUTHOR_NAME='David Bremner'" master upstream pristine-tar