[Libguestfs] How to generate the debs?

I note that a number of libguestfs-realted .deb files are downloadable here: http://libguestfs.org/download/binaries/ubuntu-packages/ I'd like to be able to build these files myself, and so I want to get my hands on the input files to dpkg-buildpackage that were used to generate these (the .dsc file, the .orig.tar.gz file, and the .diff.gz, if any). Where can I find them? I thought these files might possibly live in the git repository, so I've been trying the command git clone http://git.annexia.org/git/libguestfs.git ...but it invariably hangs after a short time.