1. Download PUIAS repo:
wget -O /etc/yum.repos.d/PUIAS_6_computational.repo https://gitlab.com/gitlab-org/gitlab-recipes/raw/master/install/centos/PUIAS_6_computational.repo
2. Next download and install the GPG key:
wget -O /etc/pki/rpm-gpg/RPM-GPG-KEY-puias http://springdale.math.ias.edu/data/puias/6/x86_64/os/RPM-GPG-KEY-puias && rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-puias
3. Verify that the key was installed successfully:
rpm -qa gpg*
4. Verify that the EPEL and PUIAS Computational repositories are enabled:
yum repolist
5. Install Git 1.8
yum --enablerepo=PUIAS_6_computational install git
Note: I am not quite happy with this solution, as it only netted me Git 1.8.3 however I do not have the time to find a better solution right now.