Seems Letsencrypt client will have Python 2.6 support removed for launch https://github.com/letsencrypt/letsencrypt/pull/630 and https://github.com/letsencrypt/letsencrypt/commit/d55c3e64c02ece84d3bb490be400a82e2069fc9b
@schoen I’d definitely make a clear note in FAQ and documentation as some folks may run into issues i.e. CentOS 6.x defaults to Python 2.6 out of the box. While CentOS 7.x defaults to Python 2.7.x.
For CentOS 6.x folks they’d need something like IUS Community YUM repo for side by side install of Python 2.7 https://iuscommunity.org/pages/Repos.html