no module named _scrypt

samsara 戝 ~leapc ➤ dd489b4|develop✓
10265 ± : bitmask --debug --danger                                                                                                                                 [1m]!
Traceback (most recent call last):
  File "/home/kali/Virtualenvs/leap-bitmask/bin/bitmask", line 8, in 
    load_entry_point('leap.bitmask==0.3.2', 'console_scripts', 'bitmask')()
  File "/home/kali/leap/leap_client/src/leap/bitmask/app.py", line 156, in main
    from leap.bitmask.gui.mainwindow import MainWindow
  File "/home/kali/leap/leap_client/src/leap/bitmask/gui/mainwindow.py", line 35, in 
    from leap.bitmask.gui.preferenceswindow import PreferencesWindow
  File "/home/kali/leap/leap_client/src/leap/bitmask/gui/preferenceswindow.py", line 28, in 
    from leap.soledad.client import NoStorageSecret
  File "/home/kali/Virtualenvs/leap-bitmask/local/lib/python2.7/site-packages/leap.soledad.client-0.3.2-py2.7.egg/leap/soledad/client/__init__.py", line 34, in 
    import scrypt
  File "build/bdist.linux-x86_64/egg/scrypt.py", line 11, in 
ImportError: No module named _scrypt

*(from redmine: created on 2013-09-11, closed on 2013-10-07, relates #4948, relates #5309)*