cubicweb-pyramid #4539193 KeyError: 'No entity named CWSession in schema' [rejected]

On a pip install with a sqlite app I get a bunch of in my debug log

2014-10-26 11:54:05 - (pyramid_cubicweb.session) ERROR: Error in _set_cookie
Traceback (most recent call last):
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/pyramid_cubicweb/session.py", line 17, in newfn
  return fn(*args, **kw)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/pyramid_cubicweb/session.py", line 102, in _set_cookie
  'CWSession', cwsessiondata=data)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/cubicweb/req.py", line 174, in create_entity
  cls = self.vreg['etypes'].etype_class(etype)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/logilab/common/decorators.py", line 66, in wrapped
  return self.__call__(*args, **kwargs)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/logilab/common/decorators.py", line 94, in __call__
  _cache[args] = __me.callable(self, *args)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/cubicweb/cwvreg.py", line 331, in etype_class
  eschema = self.schema.eschema(etype)
File "/home/arthur/.virtualenvs/cubicweb-pyramid/local/lib/python2.7/site-packages/yams/schema.py", line 1155, in eschema
  raise KeyError('No entity named %s in schema' % etype)
KeyError: 'No entity named CWSession in schema'
prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>