git版本在低于1.8之前，对于私有项目会出现401的pull失败错误，只能通过升级git版本来解决

It appears that git18 is no longer available from RPMForge, at least in CentOS 6.6. Luckily, I came across the following instructions from a GitLab CentOS recipe:

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

1. 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

1. Verify that the key was installed successfully:

rpm -qa gpg*

1. Verify that the EPEL and PUIAS Computational repositories are enabled:

yum repolist

1. 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.