You need at least git-1.6 to install the development version.
Please proceed as follows for the main branch:
git clone git://gitorious.org/yap-git/mainline.git yap
cd yap
./configure
Please proceed as follows for the development branch:
git branch --track devel origin/devel
git checkout devel
git submodule add git://prolog.cs.vu.nl/home/pl/git/chr.git packages/chr
git submodule add git://prolog.cs.vu.nl/home/pl/git/clpqr.git packages/clpqr