This is required for the official reference letsencrypt client in EL6.
nose-xcover requires coverage >=3.4, currently in RHEL6 is: 3.0.1 https://github.com/cmheisel/nose-xcover/blob/master/setup.py#L20 I've checked if older versions support an older coverage but oldest commit I could find was 3.2: https://github.com/cmheisel/nose-xcover/blob/b6026cedaa6f0e47be4bac84a3d5375925fce23d/setup.py#L20 I don't know if this will work with an older version of coverage.