Problem installing CKAN release 2.2

gistfile1.txt

---- Begin output of /home/ckan/pyenv/bin/pip install -e /home/ckan/ckan ----
STDOUT: Obtaining file:///home/ckan/ckan
  Running setup.py (path:/home/ckan/ckan/setup.py) egg_info for package from file:///home/ckan/ckan
    
    error: Namespace package problem: ckanext.stats is a namespace package, but its
    __init__.py does not call declare_namespace()! Please fix it.
    (See the setuptools manual under "Namespace Packages" for details.)
    
    Complete output from command python setup.py egg_info:
    running egg_info

creating ckan.egg-info

writing ckan.egg-info/PKG-INFO

writing namespace_packages to ckan.egg-info/namespace_packages.txt

writing top-level names to ckan.egg-info/top_level.txt

writing dependency_links to ckan.egg-info/dependency_links.txt

writing entry points to ckan.egg-info/entry_points.txt

writing manifest file 'ckan.egg-info/SOURCES.txt'

warning: manifest_maker: standard file '-c' not found



error: Namespace package problem: ckanext.stats is a namespace package, but its

__init__.py does not call declare_namespace()! Please fix it.

(See the setuptools manual under "Namespace Packages" for details.)