To "git" the latest goodies in Git 1.6.x, I like to build it on my systems rather than obtain it thru a package manager.
On Ubuntu server systems, I may be missing some Git build dependencies. I can go into the Makefile and set some values (near the top) to work around this like :
It's probably easier, however, to do this to have apt-get grab the build dependencies :
$ aptitude build-dep git-core
This may get some things you may not need (Subversion, CVS), but it makes it easier.
Then just make :
# make prefix=/usr install2
# which git
# git --version
git version 126.96.36.199