Pick the version of eg that is just a little bigger than the git version that you have, or the most recent version of eg.
You can determine your git version by running 'git --version'. eg depends on some parts of git that are not guaranteed to remain backward compatible, so newer versions of git may not work with older eg. Every once in a while I depend on some new feature of git as well. However, despite this, it's not that critical that the version match be exact. For example, eg-22.214.171.124 should worked fine with 1.6.1<=git<=1.7.4, and still worked with later git as long as you avoided using 'eg status' (sadly, status is the most likely command to break).