Comment 1 for bug 840641

Seems to have been introduced with: python-greenlet/0.3.1-1ubuntu2, reverting back seems to resolve this issue.

A more verbose (but yet still not much use):

running build_sphinx
Running Sphinx v1.0.7
**Autodocumenting from /tmp/nova-2011.3~rc~20110901.1523/doc
Traceback (most recent call last):
  File "setup.py", line 136, in <module>
    py_modules=[])
  File "/usr/lib/python2.7/dist-packages/DistUtilsExtra/auto.py", line 98, in setup
    distutils.core.setup(**attrs)
  File "/usr/lib/python2.7/distutils/core.py", line 152, in setup
    dist.run_commands()
  File "/usr/lib/python2.7/distutils/dist.py", line 953, in run_commands
    self.run_command(cmd)
  File "/usr/lib/python2.7/distutils/dist.py", line 972, in run_command
    cmd_obj.run()
  File "setup.py", line 80, in run
    BuildDoc.run(self)
  File "/usr/lib/pymodules/python2.7/sphinx/setup_command.py", line 136, in run
    freshenv=self.fresh_env)
  File "/usr/lib/pymodules/python2.7/sphinx/application.py", line 116, in __init__
    self.setup_extension(extension)
  File "/usr/lib/pymodules/python2.7/sphinx/application.py", line 259, in setup_extension
    mod.setup(self)
  File "/tmp/nova-2011.3~rc~20110901.1523/doc/ext/nova_autodoc.py", line 12, in setup
    rv = utils.execute('./generate_autodoc_index.sh')
  File "/tmp/nova-2011.3~rc~20110901.1523/nova/utils.py", line 201, in execute
    greenthread.sleep(0)
  File "/usr/lib/python2.7/dist-packages/eventlet/greenthread.py", line 30, in sleep
    hub.switch()
  File "/usr/lib/python2.7/dist-packages/eventlet/hubs/hub.py", line 177, in switch
    return self.greenlet.switch()
SystemError: error return without exception set
make[1]: *** [override_dh_auto_build] Error 1