Koha from git

To install via GIT follow instructions below..
$ sudo apt-get install git-core git-email
$ git clone git://git.koha-community.org/koha.git kohaclone
$ cd kohaclone
$ git checkout -b myinstall origin

After above steps, follow normal Koha installation instructions like
perl Makefile etc..

How to upgrade Koha from git repository

cd /your path/kohaclone

git pull

If you are upgrading from a previous installation of Koha 3, you can
use the following:

perl Makefile.PL --prev-install-log /path/to/koha-install-log
make
make test
sudo make upgrade