Como posso resolver “pkg_resources.DistributionNotFound: PySide” ao executar o Everpad no 15.04?

Question

Ao tentar executar o pad a partir do terminal, recebo o (s) erro (s) a seguir. Alguém pode me apontar na direção certa para ficar everpad e runnning? O Python 2.7 está instalado no meu sistema

Saída do terminal:

Traceback (most recent call last):
  File "/usr/local/bin/everpad", line 5, in <module>
    from pkg_resources import load_entry_point
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 3020, in <module>
    working_set = WorkingSet._build_master()
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 614, in _build_master
    ws.require(__requires__)
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 920, in require
    needed = self.resolve(parse_requirements(requirements))
  File "/usr/lib/python2.7/dist-packages/pkg_resources/__init__.py", line 807, in resolve
    raise DistributionNotFound(req)
pkg_resources.DistributionNotFound: PySide