Require a recent enough version of pycrypto and see that playbook and vault ues it.

bin/ansible-playbook

@@ -18,6 +18,9 @@
 
 #######################################################
 
+__requires__ = ['ansible']
+import pkg_resources
+
 import sys
 import os
 import stat

bin/ansible-vault

@@ -20,6 +20,9 @@
 # example playbook to bootstrap this script in the examples/ dir which
 # installs ansible and sets it up to run on cron.
 
+__requires__ = ['ansible']
+import pkg_resources
+
 import os
 import sys
 import traceback

setup.py

@@ -29,7 +29,7 @@ setup(name='ansible',
       author_email='michael@ansible.com',
       url='http://ansible.com/',
       license='GPLv3',
-      install_requires=['paramiko', 'jinja2', "PyYAML"],
+      install_requires=['paramiko', 'jinja2', "PyYAML", 'setuptools', 'pycrypto >= 2.6'],
       package_dir={ 'ansible': 'lib/ansible' },
       packages=[
          'ansible',