# For preparing GRASS Debian package run

svn co svn://svn.debian.org/pkg-grass/packages/grass/trunk/debian debiangis
mv debiangis/* .

# in this directory. It will download latest debian configuration files
# from debian Subversion server (http://svn.debian.org).
# The grass debian/ dir is under SVN control so you can't just checkout over
# the top of it from another repo. 
# You may need to adapt it to work with GRASS 7 (it's for the latest stable)

# After that, you can build current version of GRASS with

dpkg-buildpackage -rfakeroot
#  or
debuild binary

# in main GRASS source directory. After the packages are generated, you can
# install them with

dpkg -i ../*grass*deb